Fake Antivirus/Pop-Up Virus

I recently came home from college to find my family's pc heavily infected. As I have not been the one using this computer I cant give you any real idea where these viruses came from but here are the problems they are causing

-Unable to run hijackthis log/any antivirus/multiple random programs (such as games) because I get the error message "Application cannot be executed. The file ___.exe is infected. Do you want to activate your antivirus software now?"

-Fake security alearts are popping up under the pretense of being from windows security center but both do the same thing which is described directly below

-Clicking yes takes me to this website "http://os-guardpro2010.com/purchase?r=57.7" and starts a random virus scan that I know wasnt previously downloaded manually

What I believe to be a seperate virus is causing these next set of problems

-The website viagra.com pops up by itself at random times

-The website porno.com pops up by itself at random times

As stated I am unable to run the logs you want so any more info you need please let me know. I am no computer expert but I do know sometimes and ill provide you with all the info I can.

Thanks in advance for any help!

We understand that you are having difficulty running certain programs, including HijackThis. However, in order for us to help you it is necessary that you provide us with a HijackThis log, and it is possible you may be able to trick the malware into letting you do this. First, download HijackThis to a clean computer, then rename it from HijackThis.exe to any other name you want, using an .exe extension, for example... YourLastName.exe. Once you have done that, burn it to a CD (preferable to using a flash drive that may easily become infected) then transfer the renamed file to the infected computer and run a scan, then start a new topic and include your HijackThis log.

Please follow the guideline at the link below to start a new topic and post your HijackThis log. If you are unable to create and post a HijackThis log, then your only option may be to reformat your computer and reinstall the operating system.

This topic is now closed. Please start a new topic by following the HijackThis Guideline posted here, just be certain you rename HijackThis: >Guideline for posting your HijackThis log<