Which boot disk?

I have a HP Vectra VL that runs Windows NT 4.0 Service Pack 4.0. Recently, I get an error during log in “Cant find dll file (0000135)”. I went to Microsoft’s site to download a boot disk to alleviate the problem, but none of the downloads specified that error. Which other download boot disk can I use instead that will solve the problem with out wiping out the hard drive?