When you attempt to add a search provider in IE7 you receive the following error:
Error: The search provider could not be installed. This might have happened
- A required file could not be downloaded;
- The website is unavailable;
- You are not connected to the Internet;
You might want to try again later.
This seems to occur if UAC is enabled. To work around it, right click the IE7 Icon on the quick launch bar and choose Run as administrator, then re-attempt to add the search provider.