There is something v.wrong with your PC's or your installs.
This rig:
3.4ghz P4
1GB Ram
X800 Pro
Will load GWX save files in about 6 mins and that's with the combined campaign enabled.
How many active processes do you have running?
What's your 'at rest' available RAM?
What's your pagefile size?
Where is your install located? Default operating partition, c:? or other?
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