system slow to respond? slow to start up?
check these minimum and recommended quantities of RAM :
windows XP : minimum 1GB, recommended 2GB
windows vista : minimum 2GB, recommended 3-4GB
when windows runs out of RAM, it uses virtual memory, which is space on the hard disk which can be used as spare RAM. the difference in speed between real RAM and virtual is a factor of billions. also, when virtual memory is being used it means constant hard disk activity which further slows any reading or writing of files.
windows will generally use virtual memory to some small extent no matter how much RAM you have, but will use it fairly constantly if less than about 200mb of RAM is available. RAM is a cheap upgrade to solve major slowdown problems!
Monday, October 20, 2008
random restarts due to failing PSU
got a system on the bench at the moment which randomly reboots. symptomatic of CPU overheating, but the sensor readings suggest it's fine
replaced the PSU and it's solid and stable
replaced the PSU and it's solid and stable
random BSOD, display reverts to 800x600
had a system in which was experiencing random BSODs, mainly during gaming, as well as sometimes the display reverting to very low resolution modes.
i checked the system logs and the wide variety of STOP codes suggested none of them were individually worth pursuing, and that there was likely a hardware (memory) problem.
i ran some memory tests for a few hours and they came up clean, but then some internet research found an interesting quote from the MSI website (it was an MSI motherboard) that said that the default memory timings might be too aggressive and could result in an unstable system. they actually expect you to manually underclock the RAM just to get a working system!
i found this a little odd, so went to investigate the DRAM settings in the BIOS, and that's when i noticed the default clock speed for the RAM was 200mhz, the correct setting for DDR400 RAM, but the machine was only fitted with DDR333. the correct clock speed for this is 167mhz. so i adjusted the setting, and the BSODs were gone.
there still remained a problem with the displays reverting to extremely low resolutions. this was caused by a lack of power - there was only a 450w PSU powering a dual-core 64-bit processor, 2gb of RAM, several optical and hard drives, and 2 nvidia graphics cards in SLI configuration.
the problem with the displays going bad was interesting, but then i noticed that there was only a 450w power supply, powering a 64-bit dual core system with 2gb ram, several drives, and 2 nvidia graphics cards in SLI configuration. upgrading this to a 750w corsair PSU solved that problem.
i checked the system logs and the wide variety of STOP codes suggested none of them were individually worth pursuing, and that there was likely a hardware (memory) problem.
i ran some memory tests for a few hours and they came up clean, but then some internet research found an interesting quote from the MSI website (it was an MSI motherboard) that said that the default memory timings might be too aggressive and could result in an unstable system. they actually expect you to manually underclock the RAM just to get a working system!
i found this a little odd, so went to investigate the DRAM settings in the BIOS, and that's when i noticed the default clock speed for the RAM was 200mhz, the correct setting for DDR400 RAM, but the machine was only fitted with DDR333. the correct clock speed for this is 167mhz. so i adjusted the setting, and the BSODs were gone.
there still remained a problem with the displays reverting to extremely low resolutions. this was caused by a lack of power - there was only a 450w PSU powering a dual-core 64-bit processor, 2gb of RAM, several optical and hard drives, and 2 nvidia graphics cards in SLI configuration.
the problem with the displays going bad was interesting, but then i noticed that there was only a 450w power supply, powering a 64-bit dual core system with 2gb ram, several drives, and 2 nvidia graphics cards in SLI configuration. upgrading this to a 750w corsair PSU solved that problem.
Thursday, August 14, 2008
Problems with windows updates? System takes forever to shut down?
Most problems with windows updates can be fixed by one of the two following methods :
If none of your updates are installing (they all say installation failed), it's possible the windows update files have become corrupted.
Stop the windows update service - right click "my computer", click "manage" then navigate to : services and applications > services
find the automatic updates service and stop it (right click > stop)
then delete the folder c:\windows\softwaredistribution (or replace c:\windows with wherever your windows installation is), this contains all the windows update files. don't worry, the folder will be automatically recreated when windows update is next run.
start the automatic updates service again and run windows update once more. updates should be re-downloaded and should install fine.
If windows update itself fails with an error code, there are a number of causes for this. In fact at one point, installing SP3 caused this very problem!
Here's the fix.
at the run prompt, type exactly as written :
notepad c:\fix_wu.cmd
notepad will open and prompt you to create a new file, choose YES.
Note : we have to open notepad this way because we need a file with .cmd extension, any other method will always add the .txt extension.
then, inside notepad, paste the following code :
If none of your updates are installing (they all say installation failed), it's possible the windows update files have become corrupted.
Stop the windows update service - right click "my computer", click "manage" then navigate to : services and applications > services
find the automatic updates service and stop it (right click > stop)
then delete the folder c:\windows\softwaredistribution (or replace c:\windows with wherever your windows installation is), this contains all the windows update files. don't worry, the folder will be automatically recreated when windows update is next run.
start the automatic updates service again and run windows update once more. updates should be re-downloaded and should install fine.
If windows update itself fails with an error code, there are a number of causes for this. In fact at one point, installing SP3 caused this very problem!
Here's the fix.
at the run prompt, type exactly as written :
notepad c:\fix_wu.cmd
notepad will open and prompt you to create a new file, choose YES.
Note : we have to open notepad this way because we need a file with .cmd extension, any other method will always add the .txt extension.
then, inside notepad, paste the following code :
net stop wuauserv
regsvr32 /s wuapi.dll
regsvr32 /s wups.dll
regsvr32 /s wups2.dll
regsvr32 /s wuaueng.dll
regsvr32 /s wuaueng1.dll
regsvr32 /s wucltui.dll
regsvr32 /s wuweb.dll
regsvr32 /s jscript.dll
regsvr32 /s atl.dll
regsvr32 /s softpub.dll
regsvr32 /s msxml3.dll
net start wuauserv
save (NOT save as !) the file
then go to run and type "c:\fix_wu.cmd", windows will run the script and window updates should be fixed - revisit the windows update site to confirm.
Another symptom caused by this is difficulty with shutting down a system, where it would take a very long time to shut down, even on a relatively clean machine. Even manually closing processes in the task manager doesn't seem to hurry up the process, which could take well over 5 minutes. And if you don't ever visit the windows update site, you may be completely unaware of a problem with windows updates, or you may be aware of the problem but not realize that it has any connection with the slow shutdowns whatsoever.
The only information that can be found is in error message in the event viewer : "The server {9B1F122C-2982-4E91-AA8B-E071D54F2A4D} did not register with DCOM within the required timeout.", which annoyingly, doesn't really tell us anything.
However, all of these things are related, and the above (second) fix for windows updates does in fact solve the problem.
"system32" window opens on startup
simple one this. open msconfig, check the startup list, and remove any blank entries.
Restore damaged CD/DVD drives
A fairly common problem I've witnessed is that of CD and DVD drives "disappearing" from the system. Opening the device manager shows them to be present, but with the yellow exclamation symbol indicating a problem. Attempting to uninstall or reinstall the devices doesn't solve anything.
Here's the fix, it's a registry hack :
Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class
Find the key {4D36E965-E325-11CE-BFC1-08002BE10318}
then delete all VALUE data from UpperFilters and LowerFilters
Note DO NOT delete the key or the strings! only delete the VALUE data!
Exit and reboot. Problem solved.
Usual disclaimer : don't go poking around the registry if you don't know what you're doing. If you bork your system, it's your fault and nobody else.
Here's the fix, it's a registry hack :
Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class
Find the key {4D36E965-E325-11CE-BFC1-08002BE10318}
then delete all VALUE data from UpperFilters and LowerFilters
Note DO NOT delete the key or the strings! only delete the VALUE data!
Exit and reboot. Problem solved.
Usual disclaimer : don't go poking around the registry if you don't know what you're doing. If you bork your system, it's your fault and nobody else.
disabling automatic restart on system failure from the registry
If for some reason you are completely unable to disable "automatic restart on system failure" on a system which will not boot, there is another way. It's possible to disable this from the registry, which can be edited offline with the appropriate tools, for example from a system recovery boot disc.
Open regedit and navigate to :
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Crashcontrol
(note this key, specifically "currentcontrolset" may not appear depending on circumstances)
and any/all of
HKEY_LOCAL_MACHINE\System\ControlSet001\Control\Crashcontrol
HKEY_LOCAL_MACHINE\System\ControlSet002\Control\Crashcontrol
HKEY_LOCAL_MACHINE\System\ControlSet003\Control\Crashcontrol
etc...
under each one, change the value for "autoreboot" to zero.
the usual registry disclaimer applies, if you mess around with stuff you don't understand you can and probably will trash your system...!
Open regedit and navigate to :
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Crashcontrol
(note this key, specifically "currentcontrolset" may not appear depending on circumstances)
and any/all of
HKEY_LOCAL_MACHINE\System\ControlSet001\Control\Crashcontrol
HKEY_LOCAL_MACHINE\System\ControlSet002\Control\Crashcontrol
HKEY_LOCAL_MACHINE\System\ControlSet003\Control\Crashcontrol
etc...
under each one, change the value for "autoreboot" to zero.
the usual registry disclaimer applies, if you mess around with stuff you don't understand you can and probably will trash your system...!
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