I have a machine that was previously running Windows XP. Actually, several years ago it was a physical machine running Win2000 and before that NT4. I virtualized it some time back when I upgraded it to XP SP3. A clean install would of course be desirable, but there's some specialized software on that machine, which we no longer can find install media or instructions for, so I am attempting an operating system upgrade to Vista and eventually to Windows 7 or 8, if the software will still work. My testing yesterday proved that yes, the software works on Win7, however the Operating System itself (still 32-bit of course) has some problems. It's a virtual machine, the user accesses with RDP, so I can, and in fact have several times, throw it away and start over from a known working state. At this point I have uninstalled everything not needed from the XP machine, and upgraded to Vista SP2. This is when I discovered that there's a problem. Likely something that existed in the XP install but doesn't cause issues until Vista is installed. Note: due to all the same stuff happening to me yesterday, today I ran this on the XP machine prior to the upgrade: Code: secedit /configure /cfg %windir%\repair\secsetup.inf /db secsetup.sdb /verbose Windows Update. WILL. NOT. WORK. It says I need to install an update, it will close and re-open itself. I approve the UAC admin popup, then it says I need to logon as an administrator or, even more insulting, ask an administrator to complete the task for me. Excuse me, but I am the administrator, and when I approved the UAC popup, it is supposed to give admin access to the thing asking for it, is it not? I tried to turn off UAC. The checkbox is already unticked, but ticking it makes no difference, it is always unticked and never prompts to reboot so it is apparently doing nothing. I launched MSCONFIG and used the disable UAC option there, rebooted, now it doesn't prompt but still fails. Downloaded the latest System Update Readiness Tool (KB947821) and ran it. The logfile says everything is ok. Updates still fail. Ran the WGA diagnostic which says everything is fine. Updates fail. Downloaded the MicrosoftFixit.wu.MATSKB tool for Windows Update. It "encountered an error and can not continue." I have disabled Windows Defender. There's no other security software on this yet. Tried the old manual way of fixing WU (stop update and bits services, delete SoftwareDistribution folder, restart services); same result. I've tried installing several updates manually. They always fail. In desperation, I logged out of my domain admin account and logged on as the local "Administrator" to see if that makes any difference. Of course not. Even if I right-click Windows Update and select "run as administrator" whilst I am logged on as "Administrator" which is of course a member of the Administrators group, still it stupidly tells me I need to log on as an administrator or ask an administrator for help. It is at this point that I am worried my co-workers heard the many vulgar swear words I shamefully uttered. At some point in all this, I remember seeing 80070005. By the way, yesterday I completely bypassed all of this and instantly upgraded XP -> Vista SP2 -> 7 SP1 but it had all the exact same problems. Also, Automatic Updates is working properly on the original XP SP3. What can I try next, I'm out of ideas. This project has wasted two full days so far and still counting.