Spaces in Windows pathnames

This is maybe a FAQ, but I couldn't find an answer by looking around
on the net:

I have installed a Lisp implementation under "C:\Program Files" on
Windows. 

ILISP does not accept a string with spaces in the file path, but it works
if I put it under C:\tmp".

I could jost move stuff of course, but is there a way to use such
path names?

-Robert