Windows Defender fails to start services upon Installation

I have got too many HP computers with a pentium 4 class processor which is either AMD or Intel based and running Windows XP with service pack 3 as a client on a Windows 2008 SBS Domain and on this machines Windows Defender will not install at all. I have already tried to run WindowsDefender.msi program with local admin rights on the client computer and although the installation will start and goes till the EULA install, then it will immediatly stop when it reaches 80% of installation and says that "Status: Starting services" and then a popup will say that

"Windows Defender Installer Information [x]

[!] Service 'Windows Defender' (WinDefend) failed to
start. Verify that you have sufficient privileges to start
system services.

[Retry] [Cancel]"

Any help would be appreciated.

I think that due to some security software you are facing this problem and not because of the presence of malware or something else that you would have thought. You can try to access them using NNTP, for same please use the following information for your NNTP client (such as Microsoft Outlook Express):

- NNTP Server: privatenews.microsoft.com
- Account name: privatenews\spyware
- Password: spyware

Note that No password will be required via the HTTP link.

You can try to uninstall Norton, incase if you have it and then check if the problem gets fixed. If that doesnt work then you can also try to modify the registry value and check.

1. First of all click on start button, type regedit.exe and press enter.
2. After that you have to go to the following location: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender\
3. Now you have to right-click on DisableAntiSpyware, on the right-hand panel, and selectModify.
4. After that you need to enter 0, under Value data and click on OK button.
5. Now you have to close Registry Editor and restart the computer and see if this works.