A little tip for the future (in case you didn't already know

):
Check your Recycling Bin for something you deleted that you did not mean to delete. When you delete something, it goes to the Recycle Bin. If you want to get rid of it forever, then just select it and hit delete. After confirming, it will be deleted FOREVER.
Also, I would have sent the sound effect via email, so that not just anyone would be able to download it. If you're reffering to the
community modern warfare pack, then that is probably okay, since (I think) it is free for all to download. If it were a commercial product, then you might get in trouble for piracy. I am not exactly sure about that (can't remember the exact definition of piracy from KeithC's rules posts), but better safe than sorry, I like to say.

Don't mean to be annoying or rude, just wanted to make sure we all stay in the green zone.
To answer your question about the CD, did you get the free version and then buy the Build Game Upgrade? If you have your FPSC activation code, there is a way to activate it without having to reinstall the whole program... can't remember exactly how. It's somewhere in KeithC's Forum rules post, in the FAQ section I think. I'm not sure if that's what you're asking though.
If you are trying to repair the software instead of uninstalling and reinstalling it, then I can't help there; I've never tried it.
Hope things work out,
Captain Coder