Last week I had an interesting problem with Windows XP. System files had become corrupted after a power failure, and the machine was misbehaving. A repair installation left all programs and settings in tact, and after performing one, the computer was again bootable and would recognise new hardware.
The first problem after the repair installation was that XP demanded to be activate before anyone was allowed to log on. It’s challenging to activate a machine if you can’t get to the desktop. Safe-Mode (F8 at startup) lets you log in, however, and you can use the following command (User the start menu, then the Run command) to reset the activation timer:
Reboot and log in and activate Windows. Normally that is all that you need to do.
In this case, however, a second problem apapeared when I tried to start the activation procedure: I couldn’t get the window to appear. Much of the XP interface is tied together with Internet Explorer (which is why it’s important that you update it even if you don’t use Internet Explorer), and in this case Internet Explorer was broken. A reinstall fixed it, which fixed the activation and the rest of the computer.