recently got a core duo 6400, everything works fine, apps/new games
EXCEPT older games such as MOHAA : Breakthrough (or any MOHAA) and
Yuri's Revenge(Command and Conquer:RedAlert2) I love these games and
need to play them.  I searched google for help and i tried setting
affinity to either core, changing boot.ini so the computer would only
use a single core, and also a custom program called imagecfg on the
web - all these methods failed.  I am looking for a a working solution
to get these games to work, and not one of the previous methods i
already listed they DO NOT WORK, thanks

Are you running 64-bit Windows XP, or 32-bit Windows XP? Your problem
might lie there...

I love the titles you have mentioned also. Especially the C&C Titles,
I have not found a fool proof way to get these to work perfectly on
any machine it's always a little trick here and there. Although, for
your C&C titles, they released a Command and Conquer Decades for 20$,
it includes all C&C Titles that have been released, with patches,
updates, and expansions. I have run this title on numerous machines.
Dual and Single core and have not had any issues other than my
monitors not being able to display some lower resolutions such as
640x480 for the original C&C. As far as MOHAA, I am in the dark on
that series.

Although purchasing more software probably isn't something you want to
hear, it was a great deal I thought, even though I had most of the C&C
titles.