Hello Ted:
What type of account in Windows are you trying to install Windows Defender
under? If its a limited accounted, it is not supported by WD
in the beta 1 release. If its an Administrator account, I would uninstall
Windows Defender, and delete the WD folder located
at c:\program files, restart the computer and reinstall Microsoft
AntiSpyware to a non-default location such as c:\msas.
Goto start menu then control panel and to add/remove programs Remove
MSAntispy then go to Start Menu and
C:/drive then Program Files and delete the Microsoft AntiSpyware folder
Then Use your search feature(Start Menu>Search) for "all files and folders"
and delete these 3 files which will be in the Windows\system32 folder
GCCollection.dll
GCUnCompress.dll
Hashlib.dll
Then download Ccleaner and run the cleaner part and also the Issues feature
at least twice to remove all of MSAS's
registry entries that are left.
http://www.ccleaner.com/download122.asp
Then reboot.
Then download Windows Defender again from this link:
http://www.microsoft.com/downloads/details.aspx?
FamilyId=321CD7A2-6A57-4C57-A8BD-DBF62EDA9671&displaylang=en
This should then be a clean Install and not give any error's
Let us know if you have any problems
Regards
Engel