Rob & Anthony's Puzzle Page
September 2, 2009

Welcome to Rob and Anthony's first puzzle page! Following is a real-world computer maintenance puzzle that we've had to figure out. Follow along and see if you can figure it out before we do. Your score will be the number to the left.

Rob: Hey Anthony. So one of the engineers at one of our clients is having a strange problem. He says that ever since you installed Avira on his workstation, some program called "Electronics Workbench" is taking forever to load.

Anthony: Well, Avira's played pretty nicely with other software so far -- that's one of the reasons we recommend it -- but there have been a couple of minor complaints. What happens if we temporarily disable its preventive measures?

Rob: No change. I've double-clicked on the program's icon, and I can see its process in the task manager, and it doesn't seem to be stuck in an infinite loop. The engineer says that the program should finally draw its main window sometime tomorrow, and then it'll work OK ... until he tries to close it.

Anthony: Yikes. Well, after struggling around with it for a while, we've finally managed to get it up and running. It looks ancient. What's the copyright on this thing? 1996!

Rob: Yep, it's a Windows 95 program, running along on Windows XP, service pack 3.

Anthony: OK, let's turn on compatibility mode for it.

Rob: Good thinking! Unfortunately, it doesn't fix anything.

Anthony: OK, get an updated version then. This thing won't uninstall or reinstall correctly, and it's so creaky it should be condemned.

Rob: One little problem: the program was working fine before we installed Avira, and now the engineer has said that it still works fine on his home computer which is running the same updates and similar hardware.

Anthony: OK, uninstall Avira.

100 Rob: Yeah. That didn't help.

Anthony: Roll back the most recent updates that were installed.

95 Rob: That didn't help either.

Anthony: Oh, nice. A heisenbug. Our favorite! Now what?

Rob: Let's try shutting off his desktop widget, his hotsync manager, and every other funky thing that's set to load at startup.

90 Anthony: Well, Windows finishes loading a lot faster now, but still no dice. This program must have eaten one of its own configuration files or .dlls or something.

Rob: Maybe. What happens if we reboot into Safe Mode, networking off?

85 Anthony: It works! This just doesn't make any sense.

Rob: No kidding. OK, safe mode with networking on?

Anthony: Still works. So it's not a networking-related issue. There goes our next-favorite culprit.

Rob: Let's strip down the software on his system a bit, and see how close we can get it to Safe Mode. Disable all of his "run" keys from the registry, disable as many of his automatic services as possible, etc.

80 Anthony: OK, now it's working fine. Let's start turning things back on; we'll start with the services, since some of his startup widgets might need them.

75 Rob: Aaaand it's broken again. So it must be one of the services.

Anthony: Well, that makes even less sense. I didn't change those when I did the regular maintenance on his workstation!

Rob: Yeah, that's bugging me too. Let's divide-and-conquer our way through the services: enable one half, and then the other half, and so on, until we figure out which ones are causing the problem.

70 Anthony: This is absurd. Hours later, we've narrowed it down to ... the Windows print spooler?

65 Rob: Yep. We've tested this thoroughly, and it's definitely spoolsv.exe, and nothing else. Everything else on his system works just fine.

Anthony: OK, let's ask Google then. Are there any other reports out there of the print spooler mysteriously causing problems for people?

60 Rob: Yes, but most of those seem to reference actual spool files. We've looked in that hidden directory, and it's empty.

Anthony: So we're on our own then. Alright, what happens if we delete all of his printers? Maybe it's some funky printer setup.

55 Rob: With all the printers gone and spoolsv.exe turned back on, EWB slows back down to a crawl again.

Anthony: Ridiculous. Is it possible that one of spoolsv's files are damaged?

50 Rob: Maybe. So we open up a command prompt and use the always-handy, "sfc /scannow" to get Windows to return spoolsv's files to a pristine state. 15 minutes later it finishes, but EWB is still broken.

Anthony: OK. What else can the internet tell us about spoolsv?

45 Rob: Well, there are a bunch of other ports and files and such that hang around even if you delete all of the printers. Looks like it tries to keep all of the drivers just in case you ever want to install that old LPT1 printer again.

40 Anthony: Fine. Let's nuke all of it with cleanspl.

35 Rob: Nice find. OK, now EWB works, but his printing setup is trashed.

30 Anthony: So let's reinstall his HP LaserJet 5 first ... and we'll have to manually write the registry keys for his USB monitor for it, since he's using a special adapter cable for that old -- I mean, "reliable" -- bit of hardware.

25 Rob: Everything's still working fine, and now he can print there.

20 Anthony: Good. Next up is PrimoPDF, which works fine, and then two other newer HP printers left. I've got the 2020 installed, and EWB is still OK.

15 Rob: Hmm. The 2320 software is getting confused by the 2020 install, and it will only allow me to install the printer if I install all this other crap too. Also, EWB just stopped working again.

10 Anthony: What?! Oh, awesome: the 2320 didn't even install correctly, it just installed the fax portion of the printer. Let's go mucking around in spoolsv's innards and strip out everything related to the 2320 fax drivers.

5 Rob: That did the trick. EWB is happy again. So for some oddball reason, it's not compatible with a specific set of fax drivers -- and as part of the network maintenance, you've been untangling everyone's network-shared printers, and re-installing them correctly. You must have set up the 2320 software the same day you installed Avira.

Anthony: Exactly.

Rob: Nasty.

Anthony: Yeah.

Your score:

80 - 100: If you're not snooping around on our work orders, I'd love to hire you.

50 - 75: Nicely done. You must be one of those unfortunate sysadmin souls.

25 - 45: Do you work for Electronics Workbench? I'd love to know why EWB5 has this problem.

5 - 20: If it helps any, this dumb incompatibility ate a combined total of 6 hours of our time.

With apologies to Kon and Bal, who were an important influence for me during my formative programmer days. I'd rather be stepping through assembly than poking at bizarre software compatibility problems.