Thanks for the replies. I tried a fresh install of MOHAA and Spearhead but still the same problem. However, this time the error message was a little bit more informative pointing the finger at nview.dll. I disabled NView and tried another install of Spearhead, which actually installed this time.
I am most pleased, this game was worth the effort getting it to work. So, thanks for the help.
Just wondering though if it would have happened with the newer detonator drivers which are supposed to include NView 2.