Author Topic: Can't deinstall avast antivirus  (Read 4921 times)

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Offline ljetibo

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Can't deinstall avast antivirus
« on: February 16, 2011, 08:31:27 AM »
I got a call couple of days ago from a friend that his computer is acting really really weird but everything seems fine.
(of course nothing was fine it was a cesspool of useless programs and viruses)
Well anyhow I ran the cc cleaner, unistalled bunch of toolbars and games, and later on I ran defragmetation.
I wanted to install NOD32 30 days trial to scan for viruses and I had to deinstall avast.
1. In the start menu under the avast tab there is only the avast icon and none other
2. under the add/remove programs I press the change/remove button but nothing happens

acces to task manager is also impossible

well anyhow yesterday I installed nod32 and ran a scan, found and deleted 8 viruses, but the problem persist (did it despite HUGE notification that I should deinstal any previous anti-viruses in order to avoid SERIOUS issues....)

hope you can help

Offline yongsua

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Re: Can't deinstall avast antivirus
« Reply #1 on: February 16, 2011, 08:52:35 AM »
You don't need to uninstall Avast! and install ESET AV for just a computer scan.I would like to recommend you this: you want to use ESET to have computer scan)Of course,I would also like to recommend this: detection is far better than ESET)If you still insist to uninstall Avast and install ESET AV,then this
« Last Edit: February 16, 2011, 08:55:45 AM by yongsua »
Avast and ESET fan since the first day using them. :-)

Offline ljetibo

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Re: Can't deinstall avast antivirus
« Reply #2 on: February 16, 2011, 07:47:31 PM »
thanks for the fast response!

I have to deinstall avast because I'll have the computer scanned at least once a day for about a week and there's a pretty big warning that things can go seriously wrong and I have a tendency to believe those warnings.
and the avast that's currently installed is completely corrupted and doesn't really work so I was already going to reinstall it later on....

thanks for the tip about malwarebytes since eset obviously didn't fix it all the way
I'll try it out, but I'm sceptic it'll fix some stuff, but at least he'll have a clean computer....

Offline Pondus

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Re: Can't deinstall avast antivirus
« Reply #3 on: February 16, 2011, 07:52:37 PM »

Offline IWRConsultancy

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Re: Can't deinstall avast antivirus
« Reply #4 on: February 17, 2011, 04:02:03 PM »
..access to task manager is also impossible.

This is always a bad sign, and indicates either registry tampering, or a malware process running. If the latter, then unless you can stop the process first you are completely wasting your time trying to do anything else.

IMHO you need to tackle this from outside the compromised OS. You need a bootable CD, such as BartPE, Knoppix, or (my preference) UBCDWin and a portable virus-scanner. I generally use ClamWin from but any competent scanner which doesn't need installing will serve. Avast is probably an option, just not tried it yet in that scenario. Anyone have experience here?

The other point is that if you keep the computer connected to get virus updates, it might be pumping-out spam all of this time. So, best disconnect the LAN/Internet cable until you have it running a clean, LiveCD OS. You can then update the scanner's defs, scan, and upload any suspect files to for confirmation. 

That said, you have to remember that a lot of new malware downloads additional malware whilst running, so you may be dealing-with several infections, plus some 'dropper' files which might not be detected. If faced with this situation, the best answer is to 'bite the bullet' and erase the entire disk, -again from a bootable CD, NOT from within the infected OS. Alternatively, if the data is worth more than the hardware, just buy a new disk and get the computer running with this. You can always sort-out the infected one later -being careful of course not to risk a re-infection.

Hope this general advice helps.

Offline DavidR

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Re: Can't deinstall avast antivirus
« Reply #5 on: February 17, 2011, 04:52:08 PM »
Some malware regularly try to block your use of these commonly used tools in windows, msconfig, regedit and taskmgr.

I have a folder in C: that I called EmergencyUtils, this contains copies of MSConfig.exe, Regedit.exe and Taskmgr.exe, but they are renamed as malware has intercepts on these file names, see image.

By renaming the copies (save as, into the C:\EmergencyUtils folder) can get around some malware only looking for the original file name. So changing the files to MSConfig1.exe, (.com file types over ride the .exe version) and Taskmgr1.exe. You can run these manually from that folder.

This may allow you to use these tools.
Windows 10 Home 64bit/ Acer Aspire F15/ Intel Core i5 7200U 2.5GHz, 8GB DDR4 memory, 256GB SSD, 1TB HDD/ avast! free 21.8.2487 (build 21.8.6586.693) UI 1.0.666/ Firefox, uBlock Origin, uMatrix/ MailWasher Pro/ Avast! Mobile Security

Offline Daris

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Re: Can't deinstall avast antivirus
« Reply #6 on: February 18, 2011, 03:55:46 PM »
Just some suggestions...I would Use the Uninstall Avast Utillity tool,I would also Use the Uninstall eset nod 32 tool.. then I would run the CCleaner and Eusing Free Registry cleaner...After that I would do a search a few times for Avast and same for eset until all those are deleted out of your registry....Than I would Install a new version of Avast and see if it installs properly ..If it does I would Right Click on C Drive and go to Properties > Tools and do a check computer for Errors and fix them...Most Malware change your computer configuration as  to be recognized as good software By your AntiVirus or Anti Malware scanners...Also If Avast is working properly, Do a Boot Scan....If it isn't I would do the same but with Malwarebytes....Also I use Revo to Uninstall any programs...It goes through your normal software uninstaller than scans for leftovers in your registry....And I don't believe that 2 Antiviruses are OK together..If all works good do a search in your registry to see if you have Norton or any other antivirus that's still there....Good luck and I hope I was of help...
Windows XP SP3 Vista capable but Prefer SP2, Avast 6, PC Tools Firewall, Spyshelter, Malwarebytes Free, SAS Free, CCleaner, Eusing Free Reg, Wise Reg Cleaner Portable, Wise Disc Cleaner Portable, Glary Utillities Portable, ClamWin Portable scanner, Firefox portable, Revo Un installer, IE7 and Opera