How can I fix a computer that is infested with malware and is extremely unresponsive? [duplicate]
Solution 1:
I recommend reinstalling Windows
If you try to salvage the existing install you'll end up spending hours or, likely, days working on it and have nothing to show for your efforts. And even if you were able to successfully run all malware removal tools I wouldn't trust that all malware actually had been removed because, by definition, the malware authors are always one step ahead of the malware removal authors. Once a machine is infected this badly it's likely loaded with all kinds of bad stuff.
So...
- Format hard drive
- Install Windows
And, as one of the commenters suggested, you should assume that all files and data from the old install are infected and should not be trusted.
Solution 2:
Various anti-virus vendors have bootable rescue/scan CDROMs available. Two free ones are:
Kaspersky Rescue Disk 10
Kaspersky Rescue Disk 10 is designed to scan and disinfect x86 and x64-compatible computers that have been infected.
The application should be used when the infection is so severe that it is impossible to disinfect the computer using anti-virus applications or malware removal utilities (such as Kaspersky Virus Removal Tool) running under the operating system.
AVG Rescue CD
AVG Rescue CD Get your business back up and running rapidly in case of system crashes.
Removes infections, repairs files and recovers systems.
Solution 3:
I'm going to hop in here and ask more about this first, and then post my assumptions about the computer. You said that its using only 1-5% of the CPU, but its still moving slowly? While I'm not saying that it isn't riddled with viruses or anything because it could very be, I do want to point out that this is screaming faulty hardware to me. Next time you get the Task Manager open, Go check out the resource monitor. Here is a simple guide to using the resource monitor.
http://www.pcworld.com/article/241677/how_to_use_resource_monitor.html
Open up task manager and go to the Performance tab. At the bottom is a button for the resource monitor. Once its open, check out the Disk Tab at the top and look and see how long requests are taking. Looking at my computer and the computer image found on that site, I'm going to guess that for a non SSD drive, sub 100 millisecond response times seem to be what you are looking for. If the computer has more than 1 second response times for everything, your computer is going to be slow no matter HOW you boot it. Comment back on here and let us know if the disk response time is slow. If it is, you can try to run a Check disk on the drive and wait forever for it to finish and see if that fixes the problem.
Remember that this may not be the problem, but if it is, then reinstalling windows or running a virus scan won't fix the problem.
Solution 4:
To add my ideas to the mix...
Try taking the offending hard drive out and plugging it in to an external caddy, then plug this in to a working PC. You can then check the disk, run anti-virus/malware checks, defrag, etc.
Also, salvage what you can of the files you need (taking care not to copy anything that could potentially infect another PC. Obviously, make sure that the host PC has got good protection before doing this.
If after placing the hard-drive back and it still runs poorly then I'd consider reinstalling Windows. The time taken to try to solve any other issues will not be worth it.
Solution 5:
If you can boot into safe mode I would do that.
Malwarebytes antimalware is an excellent free program as mentioned above and they have just released an Antirootkit program as well although in beta release
I am also a fan of DR Web Cureit Free Antivirus (on demand scanner)
Hiren's Boot CD is probably one of the most comprehensive boot malware CDs available
It could be the case that your computer is severely fragmented and may need defragmenting in which case I recommend Ultradefrag Free Edition
Ccleaner to clean out all the rubbish on your system
All the above wont cost you a penny either.
There is an excellent article written recently on November 6th 2012 by Whinston Gordon for Lifehacker which I think would be beneficial to all, entitled "The Assumptions You Make About Your Slow PC (and Why They're Probably Wrong)". Hope you find it an interesting read !