Internet Explorer tied into OpSys and keeps downloading trash

[cw12]

Hi- First time here and hopefully doing ok-

I work for a school and we have a XP with Internet Explorer which seems to be tied into the Op System. If you try to delete it, it recreates itself within seconds. It cannot be turned off with Task Manager.
Int. Explorer keeps downloading trash about every 2 minutes whether the students have the program open or not. We are networked. I have tried the free versions of Adaware and Search & Destroy. S&D shredder cannot trash the program, it only recreates itself within seconds.
Any ideas without going out and buying a program?
Thanks much,

Thanks much,
cw12

 

[Pennanti]

Couple others to try are CWS Shredder and HijackThis.