computer powers off

hey.been awhile since ive been here, but this is the best place to be when having problems.
first i will describe what is happening.
about 8 or 9 days ago my computer started turning off on its own. i checked the vevnt viewer and noticed these:

ASCTRM service failed to start due to the following error: system cant find the file specified.

MCSTRM service ... following error: system ... file specified.

the following boot-start or system-start drivers failed to load: sptd

the sptd thing i found is related to Daemon-tools, which i uninstalled weeks ago. also, found the link to shutting down sptd and deleting it from registry.
anyway, i uninstalled my video card and am using the motherboard-integrated connection. still does it. updated graphics, usb, controllers for all. still does it. did a repair of WindowsXP. still does it. switched outlets for power. still does it. switched power strips. still does it. was running two different brand memory mods. eliminated one. still does it. ran test of Maxtor drive and ran memtest and ran Everest tests. evetrything comes out fine. still does it.
sometimes the monitor will go off when im gone but tower will remain running, just have to switch monitor back on. sometimes both go off. i have all power settings to none...no hibernation, no switch monitor off after certian time period, same for tower.
have Avg which runs daily yet finds nothing. nothing odd shows up thru hijack this or ad-aware.
tower is an eMachines with 200gb hd, P4 2600 mhz, 256 mb memory (was 512), Windows XP w SP2, FIC VG31E/VG33 motherboard, video was ATI Radeon 9600 XT but switched over to intel on board.
am at a loss but hoping it isnt PSU. never had any luck replacing those. just problems. any ideas? thanks in advance.

 

http://support.microsoft.com/kb/817194 might help w/ your ASCTRM service problem.

For the MCSTRM this is what I found -
Run regedt32 and navigate to;
HKLM\System\CurrentControlSet\Services\ServiceShortName
and looking at the Reg_Expand_Sz string in the "ImagePath" value, and using
Explorer|Search see if you can find the file and correct the path string. If
the correct path contains spaces in the dir\file name, you may need to
enclose the entire path string in "quotes" (note: the Reg_Sz string
"DisplayName" is the long-name as displayed in Control Panel|Administrative
Tools|Services)

Alternately if you don't need the service anymore, you can Control
Panel|Administrative Tools|Services "| "Service Name ", then set the "Startup
Type:" to "Disabled ". Else delete the ServiceShortName subkey.


Careful editing registrys... It could be the PSU.

 

Suggest you first check for overheating; enter BIOS Setup as soon as possible after a unexpected shutdown (usually by the DEL key before windows starts, but check the manual) and look for PC Health or similar. Bios usually shows CPU temps, current and shutdown temp if available. If you don't understand what you see, post it here.

 

hey. was going thru my tower, noticed in bios that my hard drive was set as slave. could that have been the problem? i upgraded a few months ago and didnt think to check that at the time. jumper was on master so i changed it to cable-select.
any thoughts?

 

Interesting, but you'll have to wait and see.