Welcome.
Did you do an upgrade or clean insall. If answer is upgrade install, almost everyone will give you the answer to do a clean install to get rid of the old downloads. It can be done with an upgrade DVD. If you did an upgrade, you will experience problems in the future.
If you prefer not to do a clean install and the downloads are in control panel>programs you can uninstall from there or download and use revno uninstaller which is more thorough.
If they are part of windows.old, you can delete the entire file, through, disc cleanup, and including system files.