Medieval 2 Gold Edition won't reinstall! Can anyone help?

Ok, so I uninstalled M2TW Gold Edition about a month back change the game files after I re-install it. Well, then my download crashed at about 85% every time I tried to download.

What should I do? I've already called SEGA customer support and the operator redirected me to help.sega.com, where I didn't find anything too helpful. I'd really appreciate it if someone could help me out!

I'm not sure but maybe try to clean your registry with for example Ccleaner.

And also check if any files remained and try to delete them manually first. If you're done, then do a registry clean, what Rashan suggested.

I manually uninstalled the files. I'm afraid I might have to buy a new copy.