If this is just in Outlook Expressclick here;en-us;257464
If it is in Internet Explorer:
1. Quit all programs that are running.
2. Click Start, and then click Run.
and then click OK.
4. When you receive the "DllRegisterServer in urlmon.dll succeeded" message, click OK.
If this does not resolve the problem, repeat steps 2 through 4 for each of the following files (in step 3, replace Urlmon.dll with each of the file names below):