Help installing Oblivion

A couple of months ago I had a situation where I had to reinstall Oblivion. During the install process my computer froze up and the only way to get it to start responding again was to cut the power. (I waited for a long, long time before I resorted to that and I tried everything that I could think of beforehand). Now, it appears that Oblivion is on my computer, but whenever I try to run it it crashes and sends me back to Windows. I've tried to uninstall it, even though I'm positive that it's not actually there, by using the Start Menu command, the Autorun command, and by just trying to manually delete everything. A dialog box pops up after a few seconds and says: "Setup has experienced an error. Please do the following: Close any running programs. Empty your temporary folder. Check your Internet connection (Internet-based Setups). Then try to run the Setup again." My Internet connection is spot-on. There aren't any running programs. I don't think it would matter if there were. And where the hell is the temporary folder? What is it talking about? I've gotten it to start installing again but the installer just sits there after a while, usually before it gets past %10. I'm just about ready to fasten my computer to a really big rock and drop it into the ocean. If anyone has any insight on how to fix this it would be most appreciated.

Did you try uninstalling it from "Add or Remove Programs" under your Control Panel? That's the method I always use for uninstalling software when they don't come with their own uninstall program or the install is screwed up.