Plz help .. i think i have viruses in my computer (again)?

i asked this question before but i didn't find any good answer .. so am asking it again .. PLZ help

so .. I use : Symantec AntiVirus .. and i scan my computer a lot (a lot) "full scan"

however, it's really slow "my computer memo is about 80GB" and YES i do have a lot of things, "that is my first problem"

my second one is there is a lot of windows that keep opening by it-self !!

when i close it it open another window !! it really bothers me..

the third thing .. omg .. i always hear a lady voice who keeps saying "congratulation u have been selected to receive a free apple iphone" or "laptop, PSP, 2 Ipod nano..ect" the weird thing is I DO NOT SEE ANY NEW WEB-PAGE!!!

what do you think my problem is ??

Plz help .. i think i have viruses in my computer (again)?security

the virus has been removed however seems you still have some files generated by the virus, go to command promt and delet the the startup programs ,the best solution is take backup for your files, format, reinstall , update your fresh installed operating system from internet,take buckup for this fresh installation point ,in future whatever happens you can go back to this point.

Plz help .. i think i have viruses in my computer (again)?trojan