Windows 7 won't boot passed Welcome screen after boot scan cancelled

[rockittothemoon]

My Avast recommended that I "schedule" a boot time scan.  By clicking Yes, I did not realize that it would automatically restart and scan, I thought it would schedule a time for a scan.  Anyways, the boot scan started and was taking too long and I had to cancel it to do some work on my laptop.  Now whenever I have to restart my computer, I get a black screen after the Windows 7 Welcome (logo page).  It stays black for approximately a minute or so and then it goes back to the Welcome page and black screen again. It just keeps looping like that, but never goes to the login page. 

I have been able to restart, use the F8 key, and get back in under "last known good configuration" option, and it works fine that way but I don't want to have to keep doing this.  I know it is the boot scan itself that did it, because my computer had updated avast and I ran a regular scan the same day this happened, there were no viruses, etc.   Plus, my computer is only a year old, no damages.

Any suggestions?

[thekochs]

After you did the F8 "last know good config"....have you done a restart after a good login and still loops or this solved ?

[rockittothemoon]

Yeah, it still does the same thing.  Every time I restart I have to do the last good config.  I try starting normally but it just goes through the loop and I have to use the good configuration option
 

[thekochs]

Lets see if someone more knowledgable posts a suggestion but clearly sounds like Avast is in some sort of boot loop.
If no one suggests anything then I would try..........
1) Within Windows Program Installs do a Repair on Avast
2) You could go into Avast and schedule another boot scan and this time let it complete.
3) Do a clean uninstall and re-install of Avast: http://forum.avast.com/index.php?topic=143284.0

However, the above are at best "guesses" from me.....I'd wait for a more expert person to post.
Also, do you have System Restore points set that perhaps are prior to this first boot time scan ?

[rockittothemoon]

I looked at the System restore as an option, but I did this scan back in December and the earliest restore point was 1/15/14.  So that wouldn't work. 

It wouldn't hurt to go ahead and try some of your options, so I'll do that in the meantime.

Thanks for the suggestions!

[rockittothemoon]

I tried to repair the avast under programs and features and restart but it didn't work.

UPDATE:  I was actually wrong before when I said that it kept looping from the windows logo page to the black screen.  It actually keeps looping from the page that has the F2 and F12 options to the windows logo and then the black screen just before the login page.

[thekochs]

I tried to repair the avast under programs and features and restart but it didn't work.

UPDATE:  I was actually wrong before when I said that it kept looping from the windows logo page to the black screen.  It actually keeps looping from the page that has the F2 and F12 options to the windows logo and then the black screen just before the login page.

Been along time since I ran boot time scan.....I assume after POST (your BIOS F2-F12 screen), then Windows Splash that this is where boot scan comes up before login.....do you recall ? ...it would make sense.  It sounds like Avast Boot scan is routing to the scanner then exiting because it remembers your cancel but for some reason doesn't get out clean to the login screen.......only speculating of course.

So, perhaps go ahead and re-schedule a boot-time scan and hopefully on reboot it will run.....if so, let it complete.
The other option would be to do a clean uninstall...but if it was me I'd do the above first.
These scans are very slow at first then jump in percent....then slow, then jump....in other words the progress % is not symmetric over time.

I'm sure there is a easier way than all this and this is time consuming but I'm not an expert on Avast....just a Forum poster.....so far from an expert.....thus, any suggestions I do make I want to make sure are safe.

[Alikhan]

Stupid question : Have you check if it's still scheduled @ boot time scan (possible it may carry on trying until complete)

A clean install should get rid of this issue:

1. Download Avastclear, Rejzors uninstall tool and the appropriate Avast program edition

Note: It's important you used the stub online installer from the one I linked.. NOT the offline one.

Note: You need to be ONLINE during this install (online installer works in all cases whereas offline sometimes doesn't)

http://files.avast.com/iavs9x/avast_free_antivirus_setup_online.exe
http://files.avast.com/iavs9x/avast_pro_antivirus_setup_online.exe
http://files.avast.com/iavs9x/avast_internet_security_setup_online.exe
http://files.avast.com/iavs9x/avast_premier_antivirus_setup_online.exe

Avastclear : http://files.avast.com/iavs9x/avastclear.exe
Rejzors Uninstall tool: http://rejzor.wordpress.com/avast-cleanup-tool/

2. Uninstall Avast by control panel  [If you don't have Avast in control Panel go to #4]
3. Uninstall in safe mode using Avastclear.
4. Run Rejzors Uninstall Utility in Normal Mode (removes traces avastclear doesn't) - reboot.
Check : Once uninstalled check in device manager>view>show hidden devices if there is anything related to avast with a yellow triangle.. if so, uninstall it and reboot.
5. Install the version you downloaded.
6. Reboot.

[thekochs]

Stupid question : Have you check if it's still scheduled @ boot time scan (possible it may carry on trying until complete)

Great thought.......I'm trying to suggest sledge hammer approach for what may be a need for finger tap solution......ugh !!!! 

OP, great thought above....go into Avast and see if you can un-schedule the boot-time scan ?....if so, reboot and see if OK.