Do you still remember the way Windows 98 looked? If not here is a chance to bring back the Windows 98 UI to Windows 7. Plus98 For Windows 7 is a simple theme application developed by Deviantart user which brings in the look and feel of Windows 98. The simple tool does not need any installation and works from desktop. It comes with some default themes which are actually extracted from Windows 98.
You can set the screensaver, mouse pointers and also sounds using the theme settings.
If you liked the old look of Windows 98, you can try out this theme.