SQL 2005 SP1 Installation Hangs

I am trying to install SQL 2005 SP1 on a Windows 2000 Server SP4 platform. I have repeatedly tried this, and have trashed and re-built the platform all to no avail. I keep getting the same problem. The installation hangs, using 0 CPU apparently after successfully extracting the files to disk. It leaves the HOTFIX.EXE running, and cancelling it ends the process. The HOTFIX.LOG looks like this:

5/31/2006 10:05:03.185 ================================================================================

05/31/2006 10:05:03.185 Hotfix package launched

05/31/2006 10:05:03.195 Successfully opened registry key: SOFTWAREMicrosoftWindowsCurrentVersion

05/31/2006 10:05:03.195 Successfully read registry key: CommonFilesDir, string value = G:Program FilesCommon Files

05/31/2006 10:05:03.195 Successfully opened registry key: SOFTWAREMicrosoftWindowsCurrentVersion

05/31/2006 10:05:03.205 Successfully read registry key: ProgramFilesDir, string value = G:Program Files



I have been searching various forums for an answer and have found one hit here (but no answer):

http://www.eggheadcafe.com/aspnet_answers/SQLServersetup/May2006/post26789173.asp

After reading this I cancelled the CMD.EXE instead of the HOTFIX.EXE and duly got a "Product Enumeration" popup window. The HOTFIX.LOG now looks like this:

05/31/2006 12:27:18.057 ================================================================================

05/31/2006 12:27:18.057 Hotfix package launched

05/31/2006 12:27:18.057 Successfully opened registry key: SOFTWAREMicrosoftWindowsCurrentVersion

05/31/2006 12:27:18.057 Successfully read registry key: CommonFilesDir, string value = G:Program FilesCommon Files

05/31/2006 12:27:18.067 Successfully opened registry key: SOFTWAREMicrosoftWindowsCurrentVersion

05/31/2006 12:27:18.067 Successfully read registry key: ProgramFilesDir, string value = G:Program Files

05/31/2006 16:09:34.452 Successfully opened registry key: SOFTWAREMicrosoftWindowsCurrentVersion

05/31/2006 16:09:34.462 Successfully read registry key: CommonFilesDir, string value = G:Program FilesCommon Files

05/31/2006 16:09:34.462 Successfully opened registry key: SOFTWAREMicrosoftWindowsCurrentVersion

05/31/2006 16:09:34.462 Successfully read registry key: ProgramFilesDir, string value = G:Program Files

05/31/2006 16:09:34.462 Local Computer:

05/31/2006 16:09:34.462 Target Details: PET005-5

05/31/2006 16:09:34.462 commonfilesdir = G:Program FilesCommon Files

05/31/2006 16:09:34.462 lcidsupportdir = G:sql2005sp1_ext1033

05/31/2006 16:09:34.472 programfilesdir = G:Program Files

05/31/2006 16:09:34.472 supportdir = G:sql2005sp1_ext

05/31/2006 16:09:34.472 supportdirlocal = G:sql2005sp1_ext

05/31/2006 16:09:34.472 windir = G:WINNT

05/31/2006 16:09:34.472 winsysdir = G:WINNTsystem32

05/31/2006 16:09:34.472

05/31/2006 16:09:34.512 Enumerating applicable products for this patch

05/31/2006 16:09:34.532 Found Redist 2005 product definition

And there is also now a REDIST9_HOTFIX_KB913090.LOG file which looks like this:

05/31/2006 16:09:34.582 ================================================================================

05/31/2006 16:09:34.582 Hotfix package launched

Yes I am logged on as an Administrator. Yes the SQL 2005 is off the latest MSDN CDs.

How do I resolve this issue and install SP1?