Task Pane missing after upgrade

[Roscallio]

After upgrading from 9.0 to 11d on a windows 2003 server, the task pane is completely blank. It will show or fide but there is only white space where the options should. I tried reinstalling with the repair option and running all the updates but the task pane is blank. I tried registering the .dlls mentioned in an earlier post but it doesn't fix the condition. The task pane is blank with both console and remote desktop reditions. The upgrade ran perfectly on a test installation. Does anyone know how to repair this? The basic functions are running. The installation log says successful.
Thanks

[David_Woo]

it sounds to me like the .net framework and/or MSXML is corrupt, try the following:

locate the XML msi from the installation disk, if you have downloaded the installation package, download it from downloads.microsoft.com

Remove the XML installation, and reinstall using the file obtained in the previous step.

rename the directory %systemroot%\Microsoft.NET\Framework\v2.0.50727\ASP.NETWebAdminFiles to .old.

Run a Repair on the .net Framework 2.0 installation.

Run a repair on the Backup Exec installation.

Reboot

[Roscallio]

Thanks for ths suggestions, I've run the repair on the Backup Exec several times,
I removed the installations of MSXML 4 from programs then reinstall it. I went to a test site,
http://alexfung.info/xml4test.htm
and it reported that I have versions 1, 3 and 4 available.
I renamed the .net folder you identified and repaired the installation which rebuilt the data. Rebooted and the task pane is still blank. Backups are running on the live server. It is a mostly functional installation. I tried to reproduce the problem on my test installation by removing .net, and Backup exec just won't start at all. I removed MSXML 4 and 6 installations and it BE runs and the task bar is present on the test machine after a reboot. So I haven't been able to reproduce the problem in the test computer