If you are only getting freezing in Desert Storm, I'd suspect the copy you are using being at fault even if it copied to the hard disk w/o trouble.
If you are using a retail version and/or see this problem occur a lot on other games then I'd try "repasting".
To do the latter...
1 - Open the Xbox and remove the hard disk and dvd drive.
2 - Unlatch the CPU heatsink.
3 - GENTLY pry the "legs" away from the fan retainer to free the heatsink
4 - Remove the heatsink.
5 - You will find some existing material on the heatsink, this must be totally removed. I used a little gentle scraping and a cleaner bath for electonic components. The latter "melted" the remaining material.
6 - Apply "heatsink thermal paste" to the heatsink spreading it thinly in an even coat where the CPU contacted the heatsink.
The stuff I used is available in tubes from any Electronics supplier and has a high metal content. It is white in color as it comes from the tube.
It's a heavy oily paste.
7 - Place the heatsink back in place and try not to move it, reinstall the fan and relatch.
8 - close up Xbox and play away.