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How To Diagnose a Suddenly Slow Windows Computer?
Ensign Taco writes "I'm sure nearly every one of us has had it happen. All of a sudden your Windows PC slows to a crawl for no apparent reason. Yeah, we all like Linux because it doesn't do annoying things like this, but the Windows desktop still reigns supreme in most managed LAN work environments. I'm running XP with 4G of RAM and a decent CPU, and everything was fine, until one day — it wasn't. I've run spybot, antivirus, and looked at proc explorer — no luck. There is no one offending, obvious process. It seems every process decides to spike at once at random intervals. So I'm wondering if there's a few wizards out there that know what to look at. Could this be a very clever virus that doesn't run as a process? Or could this just be some random application error that's causing bad behavior? I've encountered this a few times with Windows PCs, but the solution has always been to just add more hardware. Has anyone ever successfully diagnosed this kind of issue?" And whether such a problem is related to malware or not, what steps would you take next?
Unplug the network cable in the back and see if the problem persists. The network is a common cause of this problem.
Bottom line, if your system has a sudden dramatic change in behavior for no visible reason, wipe your drive and reinstall windows. There are nasty things now that don't show up as a process, mearly using the windows kernel to spawn another thread to do whatever it wants.
Backup your data and do the safest thing. I usually run windows inside VirtualPC which means only using it for the programs that *require* windows, not for general browsing and stuff.
Kindness is the language which the deaf can hear and the blind can see. - Mark Twain
I do not see this as easy when You deal with a bunch of RAID drives or similar setup, but booting something small (COUGH deamn small linux COUGH some disk test/recovery distribution) from CD and running it straight in memory may also help a lot in diagnosing a problem.
Just last week we had a 22 out of 22 Windows in one network shutting down network processes for no apparent reason, without any errors in log, without any HDD problems. After thorough search it seems somebody infected them with some kind of rootkit, but three AV programs could not weed it out. Only reinstalation helped.
Doing a good job is like spilling coffee on a dark suit, you feel warm all over, but nobody notices.
I just did this the other day and found one of my sticks had 1000+ errors on it.
"During My Service In The United States Congress, I Took The Initiative In Creating The Internet." -Al Gore
Actually, while I do somehow sped more time at home on my Windows gaming box than under Linux (so this isn't a blanket Windows bashing,) my superficial and uninformed impression was that, all else being equal, any Windows box I've seen seems harder hit by IO than any Linux/Unix box I've ever seen.
Yes, you can get a Linux box to crawl too, if the hard drive is stuffed and it can't swap for example. Or if the chipset isn't supported well by the drivers. (Rarer these days, but certainly possible.) Or whatever.
But Windows... seems a bit special. I mean try to copy a directory between two hard drives, or better yet from a DVD to HDD, and Windows seems to me basically stuffed. Even notepad can get about as responsive as a narcoleptic snail. And you can just about forget about, say, playing a game while that happens.
And that's before you even add such brakes as an anti-virus.
I've seen that behaviour in any Windows, from 3.0 to Vista, including a detour through NT 4.0. In fact in Vista let's just say there's a reason why so many people were pissed off at the indexer kicking in all the time.
My subjective impression is that I've yet to see Linux get anywhere near that unresponsive, in a similar scenario. Again, assuming that you don't have a nearly dead HDD and the chipset is supported in DMA mode.
But heck, even in PIO mode, I've used Linux in PIO mode and I've used, say, NT in PIO mode. (Thanks to a retarded IT department which installed the wrong IDE drivers.) Linux did obviously have poor file IO performance, but NT just freaking _froze_ for a second or two, for example, when minimizing or maximizing a window. (Presumably due to aggressive memory management which swapped more of a process out when minimized.)
Now admittedly I haven't actually programmed an OS at any point, so I'm probably talking out the arse, but I see no reason why that should happen at all. Any common source of IOWait has an interrupt. Even in PIO mode you don't have to poll until it's done. And DMA, now that was invented for the precise reason and purpose of transferring some data while the CPU services another process. It's why it's there. So there's no freaking reason for the whole OS to just twiddle its thumbs and wait. Even if one process is waiting for _paging_, you can still yield to another process while waiting for the HDD.
A polar bear is a cartesian bear after a coordinate transform.
Better yet, do the aforementioned "Reformat and reinstall clean software", then, and ONLY then, make a restore point.
THEN disable "System Restore".
At that point, the .exe can no longer be used to corrupt your restore points, but YOU can always go back and turn the service back on to access that KNOWN good system/software install if the shit hits the fan again.
MUCH easier to use a restore point then reformat.