I noticed a frame-rate problem in the game today, and after checking I found that in fact 20% of the CPU time on my machine was being spent in DPCs. After exiting the game, I found that 20% of the time was still being spent in DPCs, so clearly it wasn't me.

Since nothing in particular was running on the system, I decided to chalk it up to Windows voodoo and reboot the machine. Unfortunately, when I rebooted the machine, I found that my startup script didn't work because the command line parser couldn't find the command "subst". Never a good sign.

Fortunately, it turned out that nothing malicious was at work. Yesterday I had attempted to install the update to Pinnacle Studio DV (one of the worst pieces of software ever written by humans, but unfortunately a must-use app for my video camera's obscure video format), but the installation couldn't complete because the installer was also one of the worst pieces of software ever written by humans. So it "rolled back" the attempted installation.

But still, it managed to fuck up the environment variable settings such that the system path was no longer set properly, leading to the missing subst.

It's days like this when I really appreciate the stable environment Microsoft provides for developing and deploying software.