try the windows validation diagnostic site
http://www.microsoft.com/genuine/diag/
Here's common issues and how to resolve them
There are two possible solutions here. One is caused by a permissions problem in the registry. To fix this issue, follow the steps below: 1. Click Start, and then click Run
2. In the Open box, type regedit, and then click OK
3. Expand HKEY_CLASSES_ROOT
4. Locate the subkey HKEY_CLASSES_ROOT\LegitCheckControl.LegitCheck
5. Right-click the subkey and select Permissions….
6. Ensure that Administrators allowed Full Control permission
7. Repeat steps 3-6 for the subkey
HKEY_CLASSES_ROOT\LegitCheckControl.LegitCheck.1
If this does not fix the issue with KB905474 update not installing, download the update to your desktop and manually install it. Another reason why the validation may fail occurs when the ActiveX control for the Windows Genuine Advantage Validation Tool has been disabled. Follow the steps below to make sure the ActiveX is enabled. 1. Open Internet Explorer
2. Click on Tools, Internet Options
3. Click on the Programs tab
4. Click on the Manage Add-ons button
5. Find the Windows Genuine Advantage Validation Tool and click on it
6. Verify the Add-on is enabled, if it is not. Click Enable and Ok twice to exit back to Internet Explorer.
7. Close Internet Explorer and reopen it. Now try to validate Windows again.
A third error deals with Cryptographic Errors. If you are receiving the following information when running the WGA diagnostic tool, the problem is generally with corruption in the digital signatures of some files and they will have to be reregistered.
Diagnostic Report (1.5.0545.0):
-----------------------------------------
WGA Data-->
Validation Status: Cryptographic Errors Detected
Follow the steps below to resolve these cryptographic errors.
1) Click on Start, click on Run
2) In the Open box, type CMD and then click OK.
3) At the command prompt type the following command and Press Enter
regsvr32 softpub.dll
4) You should receive a message that DllRegisterServer in Softpub.dll succeeded, click OK
5) Repeat Steps 3 and 4 to re-register the following files- wintrust.dll
- initpki.dll
- dssenh.dll
- rsaenh.dll
- gpkcsp.dll
- sccbase.dll
- slbcsp.dll
- mssip32.dll
- cryptdlg.dll
6) After all the above files have been re-registered, type Exit at the command prompt to close it and return to Windows.
7) Restart Windows and try to authenticate Windows again.
A fourth error message you may receive when trying to validate Windows XP is
This error message occurs when you do not have appropriate permissions for the DATA folder for Windows Genuine Advantage. Follow the steps below to fix this issue or click on the link above for the Microsoft article concerning this problem.
Windows XP Professional or Windows XP Home
1. Click Start, click Run, type the following in the Run dialog box, and then click OK:
%systemdrive%\Documents and Settings\All Users\Application Data\Windows Genuine Advantage.
2. Right-click the Data folder, and then click Properties.
3. On the Security tab, click Users (username\Users) in the Group or user names section. If the Security tab is absent, you'll need to follow these steps as well.
- Open My Computer
- Click on Tools
- Click on Folder Options
- Click on the View tab
- Uncheck the option for "Use Simple File Sharing"
- Click Ok and go back to Step 2 above and try again.
4. In the Permissions for Users section, make sure that each check box in the Allow column is selected for the following permissions:
• Read & Execute
• List Folder Contents
• Read
5. Click OK, and then restart the validation check process.
If the previous steps fail, start the computer in Safe Mode and try the procedure again.
HTH... all else fails : install Linux 