Unistall error

After installing version 2.0, I navigated to the vaultservice site using
IE and noticed 1.2.2.740 was still installed.  I tried installing 2.0
again and the same outcome was the same, so I am attempting to first
uninstall Vault through add/remove.  Unfortunately this is not working
for me either.  I get the following error:
 
Error 1721.  There is a problem with this Windows Installer package.  A
program required for this install to complete could not be run.  Contact
your support personnel or package vendor.
 
The title on the error message box is "SourceGear Vault Service."
 
Any suggestions on how to remove ver 1.2.2 and install ver 2.0?
 
Thanks,
 
doug lott | the home depot at-home services | senior web developer