Funny story.

I have been on a strategy game jagg recently. Cleaning up my office I found the CD for an old game I never finished, Homeworld 2 by Relic.

This is an OLD game but I loved Homeworld and Relic’s newer Company of Heroes games so I popped it in. This is a Windows 98-era game so I figured it would scream on my PC and might still look good.

It did look great although it didn’t exactly scream. I was getting under 20fps which seemed odd but still playable.

So I saved the galaxy for a while until I got to a point where I died. I reloaded the level and *bam* my system slowed down so much it was unplayable. The mouse wouldn’t respond, the frame rate was single digits. Computer-badness.

Hmmm.

I restarted the game – same problem.

I quit the game and used Task Manager to look at the CPU load. NO processes running but the CPU was 50%.

Now that is odd. In fact, that is something I have never seen before. The system Idle process is 99% and no programs were running but one of my two CPU cores was pegged at 100% doing something.

I applied the magic Windows fix-all, a reboot. The machine came up fresh and… still 50% usage.

Very odd indeed and now a bit alarming. So I consulted the Google Oracle, although it was hard to think of a question to ask it. Eventually I found two things:

The first was Process Explorer, a Windows application I had never heard of. I installed it and looked at the results.

Sure enough, 50% of my CPU was going towards “Interrupts”. Interrupt handling not an actual process was killing an entire core of my CPU.

That is when I found the second thing. A number of people with the same problem. For them, the problem was that the IDE driver for a CD drive was reverting from DMA mode to PIO mode. A little more digging and I figured out how to tell what mode my DVD drive was in – DMA mode – but others said that sometimes what it says is wrong. I followed their instructions and uninstalled my IDE controller. Windows reinstalled it and same problem – 50% for Interrupts.

So I uninstalled, rebooted, and reinstalled. No change. Still 50% interrupts.

At this point I am alarmed. My PC is horked, it appears permanent, and I have no idea what changed or caused it.

Whenever I reach this low point, I think about the millions of PC users who have no idea what DMA and PIO modes are. What would they do? Their computer is suddenly ½ as fast and they have no idea why or what to do about it. They pray to the God of Reboot, to no avail, and then they just live with it...

Thinking of those folks always comforts me even if it doesn’t solve my problem.

So what is the funny part? I guess there isn’t one; that’s what's funny. Im sure this kind of problem happens every day to thousands of people.

At this point I really have no proof of what is wrong. I removed the DVD from the drive and got my first real clue: an error dialog.

Securom, a DRM program, popped up an error dialog – It couldn’t find the right CD.

Aha! It is not proof but it is highly suspicious.

You see, Inspector, I installed an old game on an otherwise working computer. The game installs Securom DRM but an old version that hasn’t been supported in years. Securom’s CD validation code uses some crazy calls to the CD, perhaps PIO mode, perhaps something undocumented, and my system is slowed down to 1998.

If I am really lucky, uninstalling the game will remove the offending code but that is one of the reasons I abhor games with DRM. Uninstalling them often removes the game but not the DRM system.

So here I am with a game I paid for but never played and a damaged PC. It is Monday night at 1am….