Cant Even START COD on XP
 

Ive tried reinstalling/deleting local game files and have uninstalled /reinstalled .netframework 4 over and over again along with DX and the other redistributables...
I HAVE gone from Windows 7 64 bit to XP SP3 32 bit and suspect that may be part of my troubles ...transferred Steam files directly from one hard drive to another ...any help/advice?

E6550 at 3.5GHz+ 3 GB DDR2 1066 RAM X1950Pro 256MB (yeah I know ,I know weak graphics card-but surely the game should at least start!I just get yellow reticle and then desktop

COD is DX10, not sure if it runs in DX9