Having trouble with Windows Installer 4.0 in Windows Vista

Hello,

When trying to uninstall Roxio Update Manager the following error message
appears:

The Windows Installer Service could not be accessed. T his can occur if the
Windows Installer is not correctly installed. Contact your support personnel
for assistance.

When viewing the problem details for the above error message the following
appears:

Problem signature
Problem Event Name: APPCRASH
Application Name: msiexec.exe
Application Version: 4.0.6000.16386
Application Timestamp: 4549af77
Fault Module Name: kernel32.dll
Fault Module Version: 6.0.6000.16386
Fault Module Timestamp: 4549bd80
Exception Code: c00000fd
Exception Offset: 00020a6c
OS Version: 6.0.6000.2.0.0.256.6
Locale ID: 1033
Additional Information 1: 7bc1
Additional Information 2: 7ebb433212c5c2580823c973722625a3
Additional Information 3: 1c65
Additional Information 4: bb1279f20dec4a4e67479678a156c94e

Extra information about the problem
Bucket ID: 365838431

I'm trying to unistall Roxio Update Manager to install it again. I tried to
install the Roxio CD without uninstalling Roxio Update Manager but the same
error message and problem details appear. I cannot do a system restore
because I do not have a restore point prior to the date I first tried
uninstalling Roxio Update Manager. I have Windows Vista Business 32-bit.

Any help will be greatly appreciated.

--
Thank You
Susanna