Virus on my laptop

I've been having issues with my laptop for a while. Takes a LONG time to start up & load and it's only 1.5 years old if that. I've had norton on it, have 360 now and scan on a regular basis and the only issues that arrise are tracking cookies and such.  Tonite it started to scan and came up with something called infostealler.grab something....and it took care of it.  It needed to reboot the system to totally remove the virus so i did it and now there is this file called "Thumbs" on the desktop with a green and yellow bolt looking thing and it's not fully bright on the screen like the other icons. i right clicked property's on it and it says it's a system file but i know that wasn't there previously.  I was trying to copy picture files that I've had for a long time (before issues arose) to backup because I'm taking this to somebody and the computer wont recognize the drive anymore.

Anybody know what is going on?

I right clicked the file and went to scan it with Norton 360, taking forever just to start had to use task manager to close out 360 and now the screen is frozen witth the scan stub not working message and the error reporting completed message there...along with windows task manager pane and the norton 360 behind it.

help somebody please...