Kinky is correct, its due to copy-write protection. There are security flaws with the SECDRV service, so Microsoft essentially disabled it in windows 7. There is a workaround for it though - which is to manually start the service, then install. To do this you would:
-Click start > type CMD right click it and select run as administrator
-When the black box pops up type: sc start secdrv
-Install the game, and test it to make sure its working.
-When you're done playing disable the service by typing in CMD: sc stop secdrv
You will need to have the secdrv service started if you aren't using a no-cd crack, cause its the only way windows 7 will properly recognize the disc and its contents.
This is kind of annoying to have to do though, and the XWIS multiplayer download (that kinky posted a link to) does include a no-cd crack, which would bypass the issue entirely. It also works with cncnet, and can be used to skirmish and other things, so it does have *somewhat* full functionality.
source: https://support.microsoft.com/en-us/kb/3086255
