Vista - possible virus?

i tried downloading puff the magic dragon for my brother using limewire. after the download was complete, i opened it with itunes, realized it was a virus, and i began getting popups of porn and the like. now about every 10 minutes or so, i get a blue screen, my computer crashes and restarts. ive tried to start in safe mode, and i had absolutely no internet connection. i also get a pop up everytime i sign on that says iexplore.exe is requesting permission to access my computer which i cancel everytime. any ideas as to what i can do to get my computer to stop crashing? the file from limewire was already deleted completely from my computer, so i dont know what the problem is.

Hello hiimbawbz & welcome to the Vista Forums,
To enable us to better help you, we need a lot more details about your computer.
Is your computer running SP1 or SP2?
Is Windows up to date?
What Security Program are you running? Is it updated regularly?
What antimalware program[s] are you using?
How can you be sure that the culprit has been deleted completely from your computer?[ How was it deleted?]
Did you have any computer problems prior to this current event?
etc. etc.

im not sure which sp its using, vista was already loaded in the computer when i bought it. as for security, i had a trial version of norton and havent been able to get the disk, so that ran out and had to be removed completely from my computer because it was causing problems so now im using the windows firewall and security center until i can get something else. i deleted the file and cleared my recycle bin and everything, and it seems to only crash when limewire is open. i get a message on the blue screen that says

STOP: 0x0000007F (0x00000008, 0x80154000, 0x00000000, 0x00000000)

Check in your Security Centre. What is listed under Firewall, Automatic Updating, Malware Protection, Other Security Settings?

Did you run the Norton Removal Tool?
Download and run the Norton Removal Tool

Refer to this link for MS Malicious Software Tool -
Download details: Windows Malicious Software Removal Tool

Check this link to see if it would help you.
If you decide to use it make sure that you view the Quick Tour first.
CCleaner - Home

Have a look at the programs below. Both have a free version & should help in the cleaning up of your system.
SUPERAntiSpyware.com | Remove Malware | Remove Spyware - AntiMalware, AntiSpyware, AntiAdware!
Malwarebytes.org

Have a look here too -
Protection Center - Windows Live OneCare safety scanner

Yes, and thats why you never use limewire or useless torrents.