I did a little browsing on the web and this fix seemed to have worked for a few people...
This error is often caused by a firewall or virus software running on your computer. Try the following:
First turn off your firewall or virus software if you have one before downloading.
Open a dos box (Start -> Run -> cmd)
Type in
msiexec /unregister (press enter)
msiexec /regserver (press enter)
Now try installing the program (without firewall or virus programs turned on or running)
Any luck?
Cassandra
Microsoft Windows Outreach