I just got bitten by a particularly nasty bug in an two-years-old WIDCOMM Bluetooth driver installer.

It offered to upgrade the older version that I already had. I let it do so, and it started uninstalling the previous version. All well and good. Except that I noticed it was deleting its own files, which was causing the install to not be able to proceed, or so I thought.

I had put the installer files in a directory called "bluetooth" in the root of the C: drive, and it was trying to delete everything in that directory. It couldn't delete all the files, of course, because some were in use by that very installer.

It seemed very ill-behaved for it to be deleting stuff just because a directory was called 'bluetooth', but in the interests of getting the thing installed, I ended the process, put it into a new directory, 'bluetooth-install', and started again. The same thing happened.

By now this was odd. Maybe it was deleting everything that had the word "bluetooth" in it? That was *extremely* ill-behaved. But what the hell. I stopped it again, put it in a new directory called 'sheep' (first thing I could think of), then started once more.

This time it didn't delete itself, but the process was still taking an inordinately long time. So I used the Resource Monitor in Windows 7 to check what it was doing with the hard drive. It turned out that for some reason it was scanning through the whole hard disk, presumably to find old versions of the Bluetooth software.

I was not comfortable with this at all, and a nasty thought was lurking in the back of my mind. I stopped the process again, and fired up Cygwin - a Linux-like environment I often use in Windows - to see what I could investigate.

Or, at least, I tried to. Turned out Windows was unable to find the program, and would I like to browse to find it?

Crap. Crap crap crap.

A brief look later confirmed my fears. It had been deleting every file it had come across. File paths which I had only moments ago seen it accessing in Resource Monitor were now gone.

Okay, so maybe they weren't deleted, just... hidden? Somehow? Even though I had the option set to display hidden files? I rebooted into my real Linux environment and checked.

Nope, definitely gone. :(

I had about 8GB of space free before this happened. Now I have 39GB free, and a ton of stuff I use a lot is now gone. Worse, I don't yet know exactly what's missing. I'll try to find that out when I can.

Small mercies, though: The drive is a 500GB drive and that 31GB of missing data only represents about 7% of what was on the drive. But still, 7% is a lot of stuff to suddenly go missing. :(

It turns out that I'm not the only one who's had this problem. It's a bug with the version of the installer I was trying to use - which I was using for a specific reason, namely that it was the version supplied for my laptop. (Earlier I had installed a previous version of the software for various reasons, not quite realising that I actually had a newer version in place. To be fair, it *did* warn me that I had a newer version, but I couldn't remember installing it on this installation of Windows. But even this wasn't the actual problem - everything would still have been just fine had it not been for the bug in that updater.)

So, yeah. A bit distraught now. I'm going to go cool off a bit and then try to find out exactly what's missing. It could take a while.