I ran into an interesting problem yesterday, and by “interesting” I mean really annoying and made me curse Microsoft repeatedly, again and again.

An old home PC has been having video problems off and on for several years:  It’d show an argyle-style print superimposed over whatever was on the screen.  Rebooting would sometimes fix it, but in recent months it was fairly permanent.

So I replaced the motherboard, CPU, and memory, booted up XP, and ran a repair to re-install XP with all required drivers while keeping all local data, profiles, and programs.

But upon reboot, XP demanded that I activate before I could use the computer (expected), but after I agreed to activate, it would log me in and show me my desktop, but no Activation wizard would open, nor any other program (unexpected).  It was not possible to use any Window-key shortcuts to open any windows or programs, I could only push the reset button to reboot.

Booting into Safe Mode or Safe Mode with Network would result in a prompt saying something to the effect, “This Windows activation must be activated, but it cannot be activated in Safe Mode. Please reboot and try again.”

However, rebooting to Safe Mode with Command Prompt would allow me to log in, and I could run Explorer and msc.exe from the command prompt, and get around in the system.

After some Googling, I found this article, downloaded IE8 to a USB drive, installed it via Safe Mode Command Prompt, rebooted, and happily activated away.

After running a repair install using a Windows XP SP3 disc, after booting up and logging in, you’re given the message along the lines of: “You must activate Windows before you can log on. Would you like to activate Windows now?” If you select “Yes,” which is supposed to bring up the activation prompt, nothing happens. You get to stare at your desktop wallpaper until you decide to restart your computer manually. If you select “No,” you are immediately logged out. What to do?

Anyway, I discovered an easy solution to this problem today: Just boot the machine in safe mode and install Internet Explorer 8. (You’ll need to download it from Microsoft’s web site and put it on a flash drive or something to move to the troubled machine.)

via Can’t activate Windows XP after a repair install or in-place upgrade – aaron-kelley.net.