Can't install Windows Valdation Tool

Windows Update won't progress beyond this point. As requested I've run the
Diagnostics tool and Validated and here are the results from the Windows TAB:


Diagnostic Report (1.7.0066.0):
-----------------------------------------
WGA Data-->
Validation Status: Genuine
Validation Code: 0
Online Validation Code: N/A
Cached Validation Code: N/A
Windows Product Key: *****-*****-P6XDR-CYV8Y-TWG6T
Windows Product Key Hash: JVpZOErpJ7w3XZZQICVXlXiEcOM=
Windows Product ID: 76487-640-1473184-23093
Windows Product ID Type: 1
Windows License Type: Volume
Windows OS version: 5.1.2600.2.00010100.2.0.pro
CSVLK Server: N/A
CSVLK PID: N/A
ID: {AFA72431-3B68-445A-930B-4F9489844353}(3)
Is Admin: Yes
TestCab: 0x0
WGA Version: Registered, 1.7.59.1
Signed By: Microsoft
Product Name: N/A
Architecture: N/A
Build lab: N/A
TTS Error: N/A
Validation Diagnostic: 025D1FF3-171-1
Resolution Status: N/A

Notifications Data-->
Cached Result: N/A
File Exists: Yes
Version: 1.7.18.5
WgaTray.exe Signed By: Microsoft
WgaLogon.dll Signed By: Microsoft

OGA Data-->
Office Status: 100 Genuine
OGA Version: Registered, 1.6.21.0
Signed By: Microsoft
Office Diagnostics: B4D0AA8B-531-645_025D1FF3-171-1

Browser Data-->
Proxy settings: N/A
User Agent: Mozilla/4.0 (compatible; MSIE 7.0; Win32)
Default Browser: C:\Program Files\Internet Explorer\IEXPLORE.exe
Download signed ActiveX controls: Prompt
Download unsigned ActiveX controls: Prompt
Run ActiveX controls and plug-ins: Allowed
Initialize and script ActiveX controls not marked as safe: Prompt
Allow scripting of Internet Explorer Webbrowser control: Allowed
Active scripting: Allowed
Script ActiveX controls marked as safe for scripting: Allowed

File Scan Data-->

Other data-->
Office Details:
<GenuineResults><MachineData><UGUID>{AFA72431-3B68-445A-930B-4F9489844353}</UGUID><Version>1.7.0066.0</Version><OS>5.1.2600.2.00010100.2.0.pro</OS><Architecture>x32</Architecture><PKey>*****-*****-*****-*****-TWG6T</PKey><PID>76487-640-1473184-23093</PID><PIDType>1</PIDType><SID>S-1-5-21-823518204-1788223648-725345543</SID><SYSTEM><Manufacturer>To
Be Filled By O.E.M.</Manufacturer><Model>To Be Filled By
O.E.M.</Model></SYSTEM><BIOS><Manufacturer>American Megatrends
Inc.</Manufacturer><Version>1005.003</Version><SMBIOSVersion major="2"
minor="3"/><Date>20040925000000.000000+000</Date></BIOS><HWID>144F346F0184606C</HWID><UserLCID>0809</UserLCID><SystemLCID>0409</SystemLCID><TimeZone>GMT
Standard
Time(GMT+00:00)</TimeZone><iJoin>0</iJoin><SBID><stat>3</stat><msppid></msppid><name></name><model></model></SBID><OEM/><BRT/></MachineData>
<Software><Office><Result>100</Result><Products><Product
GUID="{903B0409-6000-11D3-8CFE-0050048383C9}"><LegitResult>100</LegitResult><Name>Microsoft
Project Professional
2002</Name><Ver>10</Ver><Val>B128FD8CC4B4004</Val><Hash>Vb2e86j8DAXInLL4wCY3su2GvgU=</Hash><Pid>57058-640-0000025-16253</Pid><PidType>14</PidType></Product><Product
GUID="{91110409-6000-11D3-8CFE-0050048383C9}"><LegitResult>100</LegitResult><Name>Microsoft
Office XP
Professional</Name><Ver>10</Ver><Val>800ADD0D9B9BB75</Val><Hash>iH38yFqB8u+SmW3P3KYDAZo2/3A=</Hash><Pid>54186-752-6721865-17160</Pid><PidType>1</PidType></Product><Product
GUID="{901A0409-6000-11D3-8CFE-0150048383C9}"><LegitResult>100</LegitResult><Name>Microsoft
Office Outlook
2003</Name><Ver>11</Ver><Val>986E5543CB3EDD2</Val><Hash>+XuokzVgNI32sIPQU6b3wj0GWzg=</Hash><Pid>70173-745-3698835-55165</Pid><PidType>1</PidType></Product></Products></Office></Software></GenuineResults>

Not sure it's relevant but in case it's relevant here's the Office Results:

Diagnostic Report (1.7.0066.0):
-----------------------------------------
WGA Data-->
Validation Status: Genuine
Validation Code: 0
Online Validation Code: N/A
Cached Validation Code: N/A
Windows Product Key: *****-*****-P6XDR-CYV8Y-TWG6T
Windows Product Key Hash: JVpZOErpJ7w3XZZQICVXlXiEcOM=
Windows Product ID: 76487-640-1473184-23093
Windows Product ID Type: 1
Windows License Type: Volume
Windows OS version: 5.1.2600.2.00010100.2.0.pro
CSVLK Server: N/A
CSVLK PID: N/A
ID: {AFA72431-3B68-445A-930B-4F9489844353}(3)
Is Admin: Yes
TestCab: 0x0
WGA Version: Registered, 1.7.59.1
Signed By: Microsoft
Product Name: N/A
Architecture: N/A
Build lab: N/A
TTS Error: N/A
Validation Diagnostic: 025D1FF3-171-1
Resolution Status: N/A

Notifications Data-->
Cached Result: N/A
File Exists: Yes
Version: 1.7.18.5
WgaTray.exe Signed By: Microsoft
WgaLogon.dll Signed By: Microsoft

OGA Data-->
Office Status: 100 Genuine
OGA Version: Registered, 1.6.21.0
Signed By: Microsoft
Office Diagnostics: B4D0AA8B-531-645_025D1FF3-171-1

Browser Data-->
Proxy settings: N/A
User Agent: Mozilla/4.0 (compatible; MSIE 7.0; Win32)
Default Browser: C:\Program Files\Internet Explorer\IEXPLORE.exe
Download signed ActiveX controls: Prompt
Download unsigned ActiveX controls: Prompt
Run ActiveX controls and plug-ins: Allowed
Initialize and script ActiveX controls not marked as safe: Prompt
Allow scripting of Internet Explorer Webbrowser control: Allowed
Active scripting: Allowed
Script ActiveX controls marked as safe for scripting: Allowed

File Scan Data-->

Other data-->
Office Details:
<GenuineResults><MachineData><UGUID>{AFA72431-3B68-445A-930B-4F9489844353}</UGUID><Version>1.7.0066.0</Version><OS>5.1.2600.2.00010100.2.0.pro</OS><Architecture>x32</Architecture><PKey>*****-*****-*****-*****-TWG6T</PKey><PID>76487-640-1473184-23093</PID><PIDType>1</PIDType><SID>S-1-5-21-823518204-1788223648-725345543</SID><SYSTEM><Manufacturer>To
Be Filled By O.E.M.</Manufacturer><Model>To Be Filled By
O.E.M.</Model></SYSTEM><BIOS><Manufacturer>American Megatrends
Inc.</Manufacturer><Version>1005.003</Version><SMBIOSVersion major="2"
minor="3"/><Date>20040925000000.000000+000</Date></BIOS><HWID>144F346F0184606C</HWID><UserLCID>0809</UserLCID><SystemLCID>0409</SystemLCID><TimeZone>GMT
Standard
Time(GMT+00:00)</TimeZone><iJoin>0</iJoin><SBID><stat>3</stat><msppid></msppid><name></name><model></model></SBID><OEM/><BRT/></MachineData>
<Software><Office><Result>100</Result><Products><Product
GUID="{903B0409-6000-11D3-8CFE-0050048383C9}"><LegitResult>100</LegitResult><Name>Microsoft
Project Professional
2002</Name><Ver>10</Ver><Val>B128FD8CC4B4004</Val><Hash>Vb2e86j8DAXInLL4wCY3su2GvgU=</Hash><Pid>57058-640-0000025-16253</Pid><PidType>14</PidType></Product><Product
GUID="{91110409-6000-11D3-8CFE-0050048383C9}"><LegitResult>100</LegitResult><Name>Microsoft
Office XP
Professional</Name><Ver>10</Ver><Val>800ADD0D9B9BB75</Val><Hash>iH38yFqB8u+SmW3P3KYDAZo2/3A=</Hash><Pid>54186-752-6721865-17160</Pid><PidType>1</PidType></Product><Product
GUID="{901A0409-6000-11D3-8CFE-0150048383C9}"><LegitResult>100</LegitResult><Name>Microsoft
Office Outlook
2003</Name><Ver>11</Ver><Val>986E5543CB3EDD2</Val><Hash>+XuokzVgNI32sIPQU6b3wj0GWzg=</Hash><Pid>70173-745-3698835-55165</Pid><PidType>1</PidType></Product></Products></Office></Software></GenuineResults>


I'm running Windows XP Pro SP2 in a Custom-built PC with an Intel Pent 4
with 1 Gb RAM

I'm at my wit's end. What can I try now to install & run the Validation Tool
and thus get Updates? There are no error messages shown in the Updates
history - just 'Failed'.