I was about to post my WGA problem (factory installed Vista not showing up as genuine when it was) when I solved it myself. I am sharing my experience with Microsoft.
My WGA data until I solved it was:
WGA Data-->
Validation Status: Invalid License
Validation Code: 50
Online Validation Code: 0xc004d401
Cached Validation Code: N/A, hr = 0xc004d401
Windows Product Key: *****-*****-XY9X3-JDXYP-6CJ97
Windows Product Key Hash: xFQJU8srKsovk6p1Lk1yW93in4E=
Windows Product ID: 89578-OEM-7332157-00211
Windows Product ID Type: 2
Windows License Type: OEM SLP
Windows OS version: 6.0.6001.2.00010300.1.0.003
CSVLK Server: N/A
CSVLK PID: N/A
ID: {541E3CF7-56BE-46A4-94B6-805FB4201E47}(1)
Is Admin: Yes
TestCab: 0x0
WGA Version: Registered, 1.7.69.2
Signed By: Microsoft
Product Name: Windows Vista (TM) Home Premium
Architecture: 0x00000000
Build lab: 6001.longhorn_rtm.080118-1840
TTS Error: K:20080603163612698-M:20080602123222904-
Validation Diagnostic:
Resolution Status: N/A
I looked at incompatible software (Trend Micro, Gameguard etc, as per the Microsoft website) but had none. But I did have some parental PC time control software called User Time Control Center (released at http://www.1securitycenter.com/) which I thought might be the problem. I installed it and bingo, the validation problem went away.
