Uninstall SQL 2005 errors

Hi all,

I'm trying to uninstall sql 2005 CTP, so that I can install the standard version... but I keep on getting a whole range of errors.... I can't uninstall the ctp, and I can't upgrade with the standard version...

 This is the errorcode I got

TITLE: Microsoft SQL Server 2005 Setup
------------------------------

The setup has encountered an unexpected error while Setting Internal Properties. The error is: Fatal error during installation.

For help, click: http://go.microsoft.com/fwlink?LinkID=20476&ProdName=Microsoft+SQL+Server&ProdVer=9.00.1399.06&EvtSrc=setup.rll&EvtID=1603&EvtType=sqlca%5csqlcax.cpp%40SetInstanceProperty%40SetInstanceProperty%40x534

------------------------------
BUTTONS:

OK
------------------------------

Any Ideas?