Picture of a judge's wigThis Is Not A BLOG!Picture of a judge's wig

Date: 01/03/09

Diagnosis? Murder!

I just wish some smarty-boots would come up with a program which, whenever something goes screwy on your PC, simply states in plain-man's terms what the hell the problem is.

I referred in my earlier post (down there) to my PC running like clockwork (i.e. going cuckoo). I thought the defrag had solved it, but...ah, but back to the beginning, my children...

It started on Friday evening. The mouse cursor started freezing once per second. It's an old mouse (a Microsoft IntelliMouse™ Optical that I bought for my old 98SE rig about seven years ago), so I thought that that was where the problem lay.

Except that when I tried to go into the Mouse applet in Control Panel, it tried to install the mouse software but couldn't find it. Things started getting worse and I noticed that everything was freezing up for a brief moment every second or so. In the end, even Windows Explorer hung on me and I was forced to reboot.

When everything came back up, the freezing wasn't apparent, but I still had the mouse applet problem. So I looked for newer drivers for the mouse, found them and installed them. That seemed to sort it out for the rest of the evening.

Problem solved? Nah. On Saturday, after the machine had been running for about four hours, the momentary freezes came back. I ran Ad-Aware (although I don't think it was a good idea to 'upgrade' to the new 'Anniversary Edition') which produced a list of suspect files which had been on the system for months without being deemed dodgy. I wasted a good half hour or so online reassuring myself that I had nothing worse than a set of false-positive results. I also ran Spybot and a full Avast! virus scan. I also downloaded a new program called MalwareBytes Anti-Malware (MBAM). All these came up clean, so no solution. By this point, the Windows Explorer decided to hang again as I was trying to get to the Defrag, so I rebooted again.

When I logged back in again, I went straight to Defrag and then ran a Disk Scan on it. For whatever reason, after that the thing ran straight as a die for the seven hours before I went to bed.

This morning, it started playing up after little more than half an hour. My vocabulary at this point was not appropriate for a Welsh Sunday. This time I rebooted into Safe Mode with Network Support and went back online (dangerously, because my AV wasn't running) to look for more possible answers.

By this time, the Windows Task Manager was showing a steady ticking back and to between 0% CPU usage and 38%, with the graph looking like a bandsaw blade. I ended up rebooting back into Live Mode, then downloading and installing Process Explorer (formerly made by Sysinternals, but now put out by Microsoft because they gave the Sysinternals guys well-paying jobs in their organisation). This gives more detail than Task Manager, and it was this which gave me my first real clue. There was an entry called Hardware Interrupts which was taking about 18% of the CPU usage once per second. Hardware Interrupts - as I understand it - are where PC hardware says to the processor, "Excuse me squire, but could we have a few of your cycles for a mo', only we're right out?".

So, having established what it was, it was down to why. This didn't prove to be easy, and I browsed for quite a while (I found during this process, quite by coincidence, that Autorun had not been disabled on my optical drives as I thought it had been, although there was a Windows Update the other night which could have changed that).

Following up one possible line of enquiry, I went into Administrative Tools > Computer Management > Device Manager to see if there were any IRQ conflicts. I then clicked on Action > Scan For Hardware Changes (just to see what would happen, to be honest; I had no more idea than the Man In The Moon by this stage). Nothing visible happened, so I came out of it and went browsing for more possibilities.

I'd been doing this for a couple of minutes when I suddenly realised - it had stopped happening! CPU usage was now static and stable. Baffled, I went off to do something else for a few minutes.

Upon my return, I went back into Computer Management and - just for the hell of it - decided to check the Event Viewer. There was an entry with a big red 'X' which, upon opening it, told me that the DVD-ROM drive had disappeared. I went into My Computer and, sure enough, I had drives A, C, D and F to I, but no E, E being the DVD-ROM drive.

Suddenly, things started to fall into place. If this system has had one fault all along, it has been that the cabling into the optical and floppy drives never seems to be completely secured, and I've had to reseat them before. I then recalled that I had knocked the tower case with my foot a couple of evenings ago - not a kick by any means, but contact all the same. So, log off, power off, and cover off the tower. The cables seemed to be secure, but I knew from past experience that that can be deceptive. I did a bit of waggling and shoving, then put the cover back on and powered back up.

That, my dears, was over three hours ago. I've had Process Explorer on the whole time, and Hardware Interrupt has behaved itself just fine - only the occasional leap up to the dizzy heights of 0.78% of CPU usage. All now seems well again. The Hardware Interrupts must have been either from the system trying to find the DVD-ROM drive, or the DVD-ROM drive trying to find out where the hell it had got itself to.

It's nice to have had the training and experience from my former life as a Systems Administrator which enables me to be able to follow a line of thought like this and reach a successful conclusion, but the problem completely put paid to my plans for a productive weekend digitising more of my vinyl.

Technology - don'cha just love it?



(I was worried that my PC was going apeshit yesterday - turned out the little darling just needed a defrag (*). Anyway, to business...and Dydd Gŵyl Dewi dedwydd i chi gyd)

The notable thing about Wikipedia is that anyone can edit it.

One thing this means is that, despite wretched totalitarian Home Secretary Jacqui Smith being exonerated in yet another one of those convenient "Government appointee clears government minister" shocks, someone doesn't want to let us forget it:

Wikipedia article referring to Jacqui Smith as 'Jacqui fiddle Smith'

Tee hee.

(* No it didn't - see above)