How to delete or replace .dll files win2000 is using

I have windows 2000 and i'm having problems with dll files.
I tried to install a program but there was error telling
something like: sethandlecontext was not found on kernel32.
dll. How can i fix this problem? I found sites that suggest
of deleting files like winsock.dll & wsock32.dll and few
others, but when i try to delete them I get an error
message that says can't delete, because windows is using
this file. Is there anything I can do to delete, or replace
these .dll files? I also found out that this whole
kernel32.dll problem is because the program is designed for
win98 or something, but some people seem to have solved the
problem, but how they do it? I hope someone can help me out
with this issue, because it's very important.. thanks. (I'm
terribly sorry that the errormessages are so unaccurate,
but I have Finnish version of Win2000)