"Windows Installer has stopped working"

[Snowy]

Ok, so whenever I try to install something in Windows Vista, I get this error message saying "Windows Installer has Stopped Working". Anybody know what this means (besides the fact that it's not working), and how to fix it? It's really annoying - I can't install anything.
This is what it looks like:


Any help is appreciated!

[Patrickssj6]

Try this:
1.Click Start, point to Find, and then click Files Or Folders. 2.In the Named box, type Riched20.dll, and then click Find Now.3.In the Search Results box, right-click Riched20.dll, and then click Rename on the shortcut menu. Rename the .dll extension to .old.
Only if you don't use Outlook.