How do I delete a file under use?

I think I may have gotten a virus from some Comiket 68 files. Damn those crafty Japanese. I installed over the past week. My iexplore.exe won't close, even End Tasking it in the Task Manager won't do anything, it just stays there. A Hijackthis scan turned this out:

C:\RECYCLER\S-1-5-21-1343024091-1078081533-839522115-1003\iexplore.exe

As predicted, everytime I try to delete it, XP goes 'LOL ITS IN USE FAGGOT'
So a question: How do I delete said file, and if its under MS-DOS, how do I make XP boot under pure MS-DOS? Thanks.

>>3
I believe that doesn't work with XP, due to the command prompt only being an emulation that looks like DOS and has to make its requests through the kernel.