I can't guess why you wrote Malwarebytes is a free one time use. I see it all the time for free. IT IS NOT AN ANTIVIRUS!
Here's why I use Ninite to get these tools:
http://www.howtogeek.com/201354/ninite-is-the-only-safe-place-to-get-windows-freeware/
So go get a new antivirus and the usual scanners there.
Grif tells more at http://forums.cnet.com/7726-6122_102-5509131.html?tag=posts;msg5509131
Bob
Most days my computer Windows 7 runs very slow such as freezing up, typing won't show up for 15 - 20 sec. etc and can take 6-8 minutes to shut down pc. Four months ago I had a bad virus where I thought it had wiped my hard drive clean but could see I still had info in disk C & D so tried to do system restore but it said I needed to remove AVG to continue butt AVG wouldn't remove. Someone told me to download Malwarebytes.com, after I ran it I could than remove AVG to get System Restore to work which brought back most of my programs etc. But lately been having this slow pc problem so wondering of the virus is still there. Malwarebytes is a free one time use so can't run it again unless I buy the pay version, any other free antivirus downloads available ?

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