Virus? What can I do for it?

I let a friend use my computer and now I keep getting popups and a message that says ''Internet Explorer has encountered a problem and needs to close. We are sorry for the inconvenience. '' And so on. Is there a virus on my computer? I don't know much about the computer (this one is my husband's) so I don't know if he has spyware...is there a free program I can install to remove a virus? Please help!!! It's soooooooo annoying! Popups and this message will even appear when internet explorer isn't open!

Virus? What can I do for it?network security

if it mostly just popups then use the spyware doctor, it will find it so you can remove it,, its a malware,

Update and use your own antivirus or download one of the antivirus tools below and along with the spyware doctor and update them and restart your computer in safe mode ( tap F-8) during startup, then scan with the antivirus and the spyware doctor while in safe mode, this should find it so you can remove it; Please note that you should only run one antivirus on your computer at one time,

Avira Antivirus free (Recommended)

http://www.free-av.com/antivirus/allinon...

PC Tools free antivirus, free, Note; only run one antivirus at a time;

http://www.pctools.com/free-antivirus/

Kaspersky free antivirus; Note, you should only run one antivirus at a time;