Atomic I/O letters column #65
Originally published in Atomic: Maximum Power Computing Reprinted here January 2007.Last modified 16-Jan-2015.
IRQL Equality Now!
I recently got Need for Speed Underground 2 for my computer, and every time I get to the main menu it comes up with a error and restarts. At the top of the error it says DRIVER_IRQL_NOT_LESS_OR_EQUAL.
What's wrong with my computer?
Samuel
Answer:
Congratulations - you are enjoying what may be the definitive Mystifying
Bluescreen Error.
Different Windows versions can come up with a plethora of inscrutable stop errors, of course, but the Not-Less-Or-Equal one has the distinction of both making no obvious sense at all (even grammatically), and being quite common.
To be fair, the name's slightly informative, as is the rest of the stuff on the error screen if you've been struggling with these things long enough that your eyes naturally dart down to the lines that start with asterisks.
This failure can, as the name says, indeed be caused by various low-level chicanery that actually has to do with the Interrupt ReQuest Level (IRQL) settings for hardware. Usually, it's actually the drivers that connect the hardware to Windows that're at fault, which is good because it means you can upgrade the drivers to fix the problem - or disable the offending hardware altogether, while leaving it plugged into your computer.
The asterisk-lines in the screen shot Samuel sent me show that nv4_mini.sys is what Windows thinks caused the problem this time. As the name suggests, that file's part of the Nvidia driver suite, so the first step of your bug-hunt should be upgrading your graphics card drivers, if they're not already the current version.
This is Step One in all of the useless troubleshooting guides on game companies' Web sites, but there's a reason for that. If Windows explodes every time you run a game, then the graphics card reaching for a previously unused piece of its driver may indeed have something to do with it, even if some graphics-driver-y file isn't named on the error screen.
If this doesn't help, feel free to upgrade any other drivers you can think of. Any driver could be the culprit. On some motherboards, for instance, USB controllers that aren't even connected to any devices can cause this problem. Disabling the offending hardware in Device Manager will unload the driver and fix things, so you could go on a rampage through Device Manager disabling anything you don't actually need to run the game (including stuff you need to connect to the Internet). If that helps, you can start re-enabling things until the problem comes back.
Drivers aren't the only possible cause, though. Non-driver software conflicts of one kind or another can do it, as well. Antivirus software, for instance.
Since you're having the problem instantly and consistently at one definite time, it's probably not a gross hardware problem. Not-Less-Or-Equals all over the place are often caused by bad RAM, and you should never rule out the possibility of a bad power supply when a PC goes weird.
In your case, though, it's probably drivers.
She's gonna be a bastard to start...
I have a computer at work (in a factory environment) that has been giving me trouble ever since the really cold weather started (in Melbourne).
It runs XP Home. I have Ghosted back to old copies, before major Windows updates and other changes, and it does the same thing. It takes 4-5 minutes to boot compared to its usual 2 minutes. Sometimes a boot ends in a BSoD. Sometimes Windows won't load various files. Sometimes it can't see where the previous Windows install is. WTF!?
When it boots it does everything super slow. Defrag will not start and Scandisk (on reboot) comes up with "unreadable sector" problems.
Give it half an hour after startup and it's up and running full speed. No disk errors on any scans.
This has me really really confused, as it's never had any issues for the last 3 years. Any suggestions on a fix would be much appreciated.
George
Answer:
Sounds like a classic "stiction" problem to me.
One or both of the hard drive's two moving assemblies (the platters and the heads) are having a hard time moving until it's warmed up, for one reason or another (bearings, gooey lubricant, a weak spindle motor...). If the platters are hard to spin, the drive may periodically be falling below its normal rotational speed and putting operations on hold while it spins back up and stabilises its speed. If the heads aren't responding to the voice coil quickly or accurately enough you can get all sorts of freaky errors, or at least really crappy drive performance.
Stiction problems (it's a real, though colloquial, physics term) aren't nearly as common as they used to be - particularly back in the days when he who didn't run the special head parking program before shutting the computer down would hear an expensive noise when he flipped the switch again. But they can still happen.
Possible solutions, in increasing order of practicality:
1: Open up the drive in a very clean place, and very carefully oil the bearings.
2: Treat the computer like the Land Rover in "The Gods Must Be Crazy", and just never let it stop.
3: Get a new drive.
[George got back to me. Replacing the drive indeed did the trick.]
Also, flushing the toilet opens the garage door
When I turn my bathroom light on or off, it makes the USB game pad in my living room malfunction, needing an unplug-and-replug. This is 100% reproducible.
The light and the computer are obviously on different circuits. The only interesting thing about the light is that it is one of those 80s light-fan-heat combos.
How can this happen?
Bennett
Answer:
It's probably RF noise from the light switch - but there shouldn't be enough of it to cause that glitch.
Step one: Get a table lamp or a vacuum cleaner or a toaster or something, sit it close to the game pad, and turn it on and off. If that causes the same problem, then broad spectrum RFI is indeed the cause.
You can detect this interference, though not of course tell what's susceptible to it, by using an AM radio tuned to no channel in particular. You'll hear pops and crackles whenever something sparks nearby.
A light switch that produces lots of RFI is a light switch that's arcing a lot more than it should. That's either because it's striking one relatively long-lived arc as it switches, or because it's bouncing a lot when you switch it, striking lots of short-lived arcs. That's more likely. This can go on for years with no problems, or it can start a fire the next time you have a shower.
If the switch is as old as the combo-lamp thing, it could very easily be a mess in there. Fortunately, it's no big deal to wire in a new one.
It is, of course, illegal in numerous countries, including Australia, to do this job yourself if you're not qualified, and it's dumb to do it if you don't know what you're doing. There are also more wires involved in a multi-switch plate for heat, fan and light than there are in a normal light switch, so it's much easier for a novice to screw up.
You have been warned.
But I only download porn, officer!
A workmate of mine is being accused by his ISP (TPG) of illegally downloading SWAT 4. They have served him with a notice and are not responding to his requests to show proof (on this charge he is actually innocent, he doesn't bother with downloading games). However he has ten working days in which to prove his innocence, and with TPG ignoring him it's hard for him to proceed.
Going through the Telecommunications Industry Ombudsman will likely take longer (and the ombudsman usually wont touch anything until there have been various avenues of resolution followed), so I've told him to make a post on the Whirlpool forums as well.
Have you got any ideas on what he can do to proceed or get a response from TPG?
Steve
Answer:
I don't know much about this, but Electronic Frontiers Australia probably do.
They don't give legal advice, but that's not really what you're after here, and they're a good source of references to other people. Get your friend to phone them, not e-mail.
Note that the agreement that everybody ignores when they sign up with their ISP invariably includes clauses that allow them to cut you off for any reason they like, and actually taking something like this to court is pointless unless the ISP (or the media anti-piracy protection racket of your choice) is making you go there themselves, or threatening you with something worse than losing your Internet connection.
That, of course, is no reason to not be angry with the ISP and do your darndest to make 'em famous on Slashdot for the week.
Holy water usually makes things worse
Now my wife hates me even more. Usually she only uses the Dell for Mah-jongg but its non-availability, due to my error, is a major issue. I moved (only a tiny bit!) the computer, and now the LCD screen is black. Tried on-off and new-video-cable and analogue-cable-instead and look-inside-to-see-if-the-video-card-has-shifted things, all to no avail.
How can you troubleshoot a PC with no screen?
Help me, Obi-Dan Kenobi, you're my only hope...
David
Answer:
I don't have a definite answer for you, but I can give you some more pointers.
Does the machine beep once, as usual, on startup? If so, then it's passing its Power-On Self-Test (POST). If there's a fundamental hardware problem then you'll get multiple beeps on startup, or no beep at all.
Do you have another monitor, or another computer on which to try the Dell monitor? My best guess at the moment - which is just a guess - is that the Dell monitor just chose that moment to drop dead. Modern monitors let you access their On-Screen Display even if there's nothing plugged into them - and they usually have their own special nothing-plugged-in notification as well - so you can do some basic troubleshooting that way, too.
(David got back to me. The problem was a diabolical combination of a dodgy cable and a dodgy video card. Replacing both components cured it.)
