Author Topic: Uninstall Avast if computer won't load into Windows?  (Read 11680 times)

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Offline johns2947

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Uninstall Avast if computer won't load into Windows?
« on: January 26, 2015, 08:15:44 PM »
Hello

A friend brought me her computer which would no longer load into Windows. Its a Dell E521 with 3 GB RAM and 512 hard drive. The hard drive failed about a year ago and was replaced. The computer has run fine since.

It runs Microsoft Vista and she had installed the paid version of Avast some time ago.

Her hard drive was partitioned into C:, E: and F: and the C: partition (about 100 GB) was almost full, so she asked about taking some of the free space from E: and merging it with C:

I recommended the free disk partitioner "Easeus Partition Magic" which I have used many times. She installed it and I walked her through the changes she wanted to make. She was able to repartition the drive, and successfully rebooted the computer into Vista. She opened her Outlook and was in the process of sending me an email to report her success when the computer crashed.

She had to shut it off by holding in the power button. After that, Windows would not load.

She is fairly computer literate, so I had her boot into the Troubleshooting menu (the Safe Mode menu). Booting into Safe Mode gave the same problem. The computer would boot, then begin to load Windows, then go to an all-black screen with only a white cursor arrow. She could move the arrow around the screen, but anything she tried to click on (either left or right click) produced no response.

The computer would not continue to load Windows past this point and all attempts to CTRL+Alt+Del or other keyboard functions were ignored. The only way to shutdown the computer was to hold in the power button.

When she brought me the computer, I tried "Last Known Good Configuration" and all of the other options in the Troubleshooting menu, but each gave the same results. The only difference was that booting into Safe Mode gave a black screen with a larger white cursor arrow, indicating that the screen was at the lower resolution of Safe Mode.

I was able to boot the computer successfully using a Linux Live CD (Puppy Linux) and was able to read the Windows partition and see the files there.

I booted the computer with her Windows install disk, and chose "Repair". The automatic Repair function started, but took forever to run and I finally gave up and rebooted.

This time I ran chkdsk /f from the Command Prompt in the Repair section. Checkdisk found hundreds of errors, which it fixed  and reported no other problems. When I rebooted with the Repair disk and re-ran the automatic Repair it completed in a few minutes, reporting there were no errors.

I rebooted the computer normally, and it got to a black screen with a white cursor and froze.

I rebooted the computer to the Troubleshooting menu and selected "Enable boot logging", which makes a text file in the Windows folder showing the boot progress.

Restarting the computer with Linux I was able to read the boot log file ... the last entry was :

"Unable to load C:\Program Files\Alwil Software\Avast5\ng\vbox\vboxaswdrv.sys"

Using Linux I found that file and renamed it, hoping that if the computer couldn't find it, it would just skip over it.

Rebooting the computer gave the same problem: black screen with white cursor, nothing else.

I searched Google for that filename and eventually came to the Forums here. Not seeing that exact problem mentioned, I decided to install the latest Avast free onto my own computer, and copy the vboxaswdrv.sys file from it to her computer. If the problem was that the file had somehow gotten corrupted, this might fix it.

After copying the file, I rebooted her computer and got the same problem.

It was getting late, so I decided to shut it all down for the day. When I tried to turn off my computer (Windows 7) it would not shutdown! It acted like it was going to, but then just froze up and sat there showing the Desktop.

I had to power it off to shut it down.

As I had read on the Forum of others having this problem, I rebooted my computer, downoaded the Avast clear uninstaller tool, uninstalled Avast and reinstalled Windows Security Essentials. The computer is fine again and I'm using it right now to type this.

I have used the free versions of Avast almost exclusively over the years, and always recommended it to anyone who would listen. Only in the last year have I had to uninstall it. Whenever new virus definitions came out, Avast would notify me that it needed to be updated, but would not do it without me actually telling it to.

It would not just go ahead and update itself on its own. I got tired of the nagging, so switched to Security Essentials, which keeps itself updated without nagging me.

Sorry for the long post, but it was necessary so that you could understand the situation her computer is in.

I have finally decided to reinstall Vista into another partition (which completed successfully) and the computer is running the Windows updates now.

The new installation cannot access the old Vista partition for some reason, but I can use Linux to move her files from the old partition to the new one.

At this point, I cannot say for sure that Avast is the cause of her problems, but the failure to boot past the Avast entry in the boot log is suspect. I cannot determine what caused the computer to crash in the first place, but I am suspecting that perhaps the Avast she had on the computer did an automatic update behind the scenes, and this update is incompatible with the computer somehow.

As I can't boot into the old partition, I cannot remove Avast to prove or disprove this suspicion.

Is there a way to remove or disable the Avast installation in the old Vista partition?

I have even taken the extra steps of manually replacing the registry hives with older versions. In Vista, in the System32\config folder, there are current hives, and also copies of earlier hives, such as "Default" and "Default_previous", "SAM" and "SAM_previous" etc. I have renamed all the old hives, and then replaced them with the "previous" versions, but when booting the computer I get the same problem as originally ... black screen with white cursor only.

Is there anyway to remove Avast from a Windows partition that won't load?

thanks

Offline thekochs

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Re: Uninstall Avast if computer won't load into Windows?
« Reply #1 on: January 26, 2015, 08:53:47 PM »
Wow, great info and effort ! .....Vista 32 or 64 ?

Personally, I'd also would have run offline SFC.
http://www.winhelponline.com/blog/run-sfc-offline-windows-7-vista/

Also, I will PM Essexboy and perhaps he can blow away Avast using Fabar (FRST) fixlist but he'll need log of bad partition.
https://rufus.akeo.ie/
http://www.bleepingcomputer.com/download/farbar-recovery-scan-tool/
I could PM you RC link but of you have PC running already on other partition I think you can use off USB stick and run for bad partition. Anyway, he will need your FRST log of the bad Vista partition.
I attached the typical "flow" of how this works on a un-bootable PC.

Lastly, if it was me and you had new O/S partition working with data copied over I'd stick with it and use partition magic to reclaim old Vista partition as free space.  I would definitely copy back the original hives from the clean Vista install.....the old ones are clearly corrupt.

« Last Edit: January 26, 2015, 11:15:22 PM by thekochs »
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Offline johns2947

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Re: Uninstall Avast if computer won't load into Windows?
« Reply #2 on: January 26, 2015, 10:14:12 PM »
It's 32 bit.

I will run SFC offline (I knew about SFC, but did not know about the offline feature!)

And will run FRST and post the log here.

Thanks for the ideas and the quick response. Yes, the new installation is running fine, but the old partition has (of course) lots of additional programs that she would like to keep using. She will have a tough time re-acquiring all that stuff, so if I can get the old partition to load, that will be a better solution.

Notice that I say "load" not "boot" ...the computer seems to boot just fine ...it is only once it is done booting and is partially into Loading Windows that it fails. It does not seem to be a boot problem.

Thanks again. I'll get back to you.

Offline thekochs

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Re: Uninstall Avast if computer won't load into Windows?
« Reply #3 on: January 26, 2015, 11:05:08 PM »
It's 32 bit.
will run FRST and post the log here.
Be sure to run the 32bit version of FRST.exe

Notice that I say "load" not "boot" ...the computer seems to boot just fine ...it is only once it is done booting and is partially into Loading Windows that it fails. It does not seem to be a boot problem.
That's good.....MBR & BCD are good.....sounds like a registry problem....hence I'd stay away from messing with those hives on new install....keep that new partition/install clean.

Since you seem to be very tech savy you can also try restoring the backup Hives on bad partition.
http://www.registryfix.net/restore-registry/  .....but FIRST if you can post FRST log lets see what Essexboy can do (eg. Registry Backup restore, Restore Point, Avast delete or even something he sees that is problem) with a fixlist.....may be alot simplier.
« Last Edit: January 26, 2015, 11:31:29 PM by thekochs »
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Offline zorgon

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Re: Uninstall Avast if computer won't load into Windows?
« Reply #4 on: January 26, 2015, 11:54:00 PM »
If you want to boot to the previous Vista install take a look at SuperGrub2. If it sees the previous Vista OS under Everything should be able to boot to it.

http://www.supergrubdisk.org/super-grub2-disk/

Offline johns2947

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Re: Uninstall Avast if computer won't load into Windows?
« Reply #5 on: January 27, 2015, 01:45:06 AM »
To Zorgon:

Thanks, but I have EasyBCD installed on the working version of Vista, have added an entry in the Boot menu for the Old version of Vista and have tried booting from it. Same problem. Black screen with white arrow cursor, nothing else.

But then if I was able to boot to the old version of Vista, I would not have had to come to this Forum in the first place  ;)

Offline johns2947

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Re: Uninstall Avast if computer won't load into Windows?
« Reply #6 on: January 27, 2015, 01:58:18 AM »
To theKochs

I am not messing with the hives from the new install ..

Thanks for the link to the registry fix site, but it seems to be for XP. Vista is much different. For instance, there is no "C:\Windows\repair folder that the site refers to!

Older copies of the hives are stored in the system32\config folder along with current versions. That is why you may remember me saying that I renamed "Default" to "Default_" and then renamed "Default_previous" to "Default".

Each of the hive files (there are six in Vista) have a copy in the config folder that are named "_previous".

There is also a RegBack folder, but the files in there were too new! They had apparently been created after the problem started (they are dated jan 22 and the problem started around jan 19)

The "_previous" files were all dated Apr 6, 2014, so they were my best choice for restoring the registry manually. This computer does not seem to have any restore points (System Volume folder on all of the old partitions is empty)

As for sfc and frst, I ran them, then remembered that I had already changed the Registry files to the Apr 2014 ones, so I had to go back and manually rename the registry files so that they would be the most recent ones, so that you could pass the results on.

After doing so, sfc won't run, yielding a 0x80000003 STOP error. I looked that up, but the few solutions on Google appear to be centered around running something when not logged as Administrator.

As I am running from the Repair console, this is not the problem.

I have renamed the registry files and restore the Apr 2014 ones. I am running SFC on it now, and will then run FRST and report back.

thanks

Offline johns2947

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Re: Uninstall Avast if computer won't load into Windows?
« Reply #7 on: January 27, 2015, 02:12:19 AM »
Ok, restored the registry files (manually) to the Apr 2014 ones, which should be good.

Ran SFC /scannow /offbootdir=d:\  /offwindir=d:\windows

and it reported that it ran successfully and found no problems

(and yes, D: is the correct partition for the old Vista install)

Ran FRST and the text file is attached to this.

thanks

Offline thekochs

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Re: Uninstall Avast if computer won't load into Windows?
« Reply #8 on: January 27, 2015, 02:25:12 AM »
Yup, no restore points.......and the last reg backup is 1/21/15....you said problem started 1/19/15 ?
Did the FRST run give you a Addition.txt file too ?

Good to hear SFC found no issues.....perhaps no O/S corruption.

I'll have to defer to Essexboy to take a look at the log.......he is the expert.....not me.
You covered ALOT of ground.......you are clearly a 1%-er in the Forum......details/effort is amazing.
At min Essexboy may blow away Avast with a fixlist.....not sure what else he'll see and do.
I PMed him.....he is UK based.
« Last Edit: January 27, 2015, 02:38:37 AM by thekochs »
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Offline johns2947

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Re: Uninstall Avast if computer won't load into Windows?
« Reply #9 on: January 27, 2015, 04:05:11 AM »
I do not see an Addition.txt file on the flash drive I used.

is that needed? how does one get it?

thanks for all your help .. will wait for Essexboy

Offline essexboy

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Re: Uninstall Avast if computer won't load into Windows?
« Reply #10 on: January 27, 2015, 03:49:10 PM »
This fix will remove Avast and its driver from the C: drive

Download the attached fixlist.txt to the same location as FRST
Start FRST and then press Fix
Once it has completed then reboot the computer, you may need to run a startup repair

Offline johns2947

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Re: Uninstall Avast if computer won't load into Windows?
« Reply #11 on: January 27, 2015, 08:35:05 PM »
Thank you for sending that file.

I ran it as instructed, then ran Startup Repair, which failed.

I rebooted to the Recovery Console and ran Startup Repair, which completed successfully. It had found a corrupted Boot Manager file and repaired it.

Upon rebooting into Vista on the hard drive, I again have the same problem ... black screen with only white arrow cursor.

I no longer wish to spend any time on this computer. I have already reinstalled Vista into a separate partition, which runs fine, and was only pursuing this to see if Avast was the cause of the problems. Having removed Avast by using your utility, I believe I have proven that Avast is NOT the cause of the problem.

As a side note, the symptoms also suggested to me that it is possible that some automatic Windows (or other) update is incompatible with the video chip on this computer, so I installed a standalone video card and set the BIOS to display to it.

Same problem.

So, again, thank you for your help in this matter. I have been a long time fan of Avast and did want to prove that it was not the cause.

She will be happy just to get her computer back in working order, with her personal files (although not programs) restored.

You may mark this thread as closed.

john