How can I get Oblivion to work again on my computer?

Awhile ago I uninstalled oblivion and then had to restore my computer to an earlier date for something. The oblivion icon reappeared but when I put the disk in it said it wouldn't play and I think it's because of SecuROM. I really want to play this game that I bought yet it won't let me. The Oblivion icon is still on my desktop and if there is a fairly simple way to solve this so that I don't screw up anything, please tell me.