Don't worry — the setup program can't have actually erased anything, so the bulbs and music are still on your disk, even if they aren't showing in the list.

What probably happened is that you changed the suggested directory in the setup program, telling it to install Holiday Lights in a different folder than the one it suggests. If you do that, it will install a brand new copy of Holiday Lights in a new folder, rather than upgrading the old one in the old folder.

Whatever the reason, the entire old copy of Holiday Lights, with all your bulbs, music and pictures, is almost certainly still on your disk. You can find it by doing this:

1. Click on the Start button
2. Choose Find...
3. Choose Files or Folders...
4. Type "Holiday Lights.exe" into the resulting window
5. Change Look in: to "My Computer"
6. Press Find Now

You'll probably find two copies of the program (normally there should be just one). If so, look at where each copy is, then open those folders — you'll see all your bulbs and music in the old folder. You can then move them to the new folder and throw away the entire old copy.