No Recovery Disk

Well, first of all I want to say I don't know anything about computers. I have a Toshiba Satillite L25. Lately I have been having a whole lot of (nude adult sites) pop ups. Laptop has been slow. When turning on my laptop and putting my password in, I'll have to wait about five to ten mintues til I can actually use it. I've been told I might have some kind of Virus. I scanned my laptop with different programs and none were detected. So one of my co-worker told me to format my laptop. But I lost the recovery disk that came with my laptop. If I format, I will lose everything right? Even the programs that came pre installed? I've heard of Backing up files, how does that work? Can you choose which files you want to back up? Sorry if I am asking too much information, it's because I know nothing about computers. I tried to get help from Toshiba tech but they were gonna charge me... so I'm hoping someone is nice enough to let a dumb girl know about PCs.

Thanks so much.

 

Follow the directions here;
http://www.windowsbbs.com/announcement.php?f=41

When done post the HijackThis log here;
http://www.windowsbbs.com/forumdisplay.php?f=41

 

Another possibility that may help now and/or in the future.