So, I spent another evening of my precious life-time wrangling with Windows Vista. I wouldn’t even try to bore you to death with the story, but apparently this particular problem has never before bitten anyone who has taken it to the Interwebs, so I might save some poor soul later on from going through the same bullshit.

What happened? Two days ago, the tablet PC functionality on my ThinkPad X61 stopped working. In my Windows session, the pen simply would not do anything. Trying to calibrate the pen through the control panel would do nothing, the button would go grey and no calibration ever appear. Even funnier, Windows Journal would refuse to start – first doing nothing, then sometimes showing an error message

Windows Journal cannot start. There was an error initializing inking components.

I also noticed that the “busy time” before a freshly started Windows session actually became responsive had increased and noted that the mouse cursor went downright choppy for some time after startup. My eventvwr application log was littered with entries of the form

Faulting application WISPTIS.EXE, version 6.0.6001.18000, time stamp 0x47918ff4, faulting module WISPTIS.EXE, version 6.0.6001.18000, time stamp 0x47918ff4, exception code 0xc0000005, fault offset 0x000198d4, process id 0xed8, application start time 01c976a1e13e22eb.

(with a bunch of different fault offsets as well, but exactly one crash per reboot, at the end of the mouse choppiness period)

I first thought that this was some kind of bitchy reaction to the fact that I had incidentally used the pen in Linux for the first time in ages the day before to annotate a plot in GIMP, but after a lot of unsuccessful searching and installation/uninstallation/reinstallation of component drivers and updates, I found out that the problem was in fact caused by attaching a new external monitor the day before – for some reason, in Windows’ multi-monitor numbering scheme that you can see in the display settings dialog, my internal display had ended up as number 2, with the (unattached) external monitor as number 1. This didn’t bother the ordinary course of Windows, since the primary monitor is ostensibly not dependent on that numbering, but apparently something in the tablet layer is convinced that the pen has to be used on display number 1 – as soon as I reattached the monitor and jiggled the primary monitor selection long enough to get my internal display back to number 1 (and did the obligatory reboot), I had myself working tablet services again.

Well, I have high hopes for Windows 7…