The Windows Installer Services could not be accessed

Hi folks,
I am using windows installer 4.5, which is very recent by the way and am running it on windows XP Pro SP3.
Recently I tried to install Microsoft Visual studio 2008 and it gives me the following error,

Windows Installer
The Windows Installer Services could not be accessed.
This can occur if you are running Windows in safe
mode, or if the Windows Installer is not correctly
installed. Contact your support personnel for
assistance.
First I thought that my Visual studio 2008 Microsoft Installer package was the problem, but this is not the case, as I have tried to add or remove other programs but get me the same errors. I have previously used windows installer 3.0 and had no problem with him.
How can I correct this error?
Do or should I just go back to my previous version of Installer?
Thank you all.
