Been having a power up problem for a few weeks now. usually happened when i tried turning the pc on at the start of the day and nothing would happen. To solve this i would turn of the flip switch at the back of the comp for a while till all lights went off, then flip it on and the pc would power up only to randomly turn itself off during the pre windows loading. I would have to do this a few times before it made it into windows. once in windows the pc would always be stable and never switch itself off.

Now no matter how i try i cant get it to power up at all for the past few days, when i flip the power switch at the back on, the motherboard light comes on but thats all. I tried the test where you unplugg everything and hold the front power button to discharge any static elec but that doent work. Would appreciate any other ideas...

You try testing it out with another power supply? Sounds like at first glance that your power supply maybe going out.

It could be the power supply...could also be overheating due to dust build up or bad CPU fan.

Failing power supplies are common and can cause your symptoms.
Check your PS.
See response 4 in this:
http://www.computing.net/hardware/w...

i have a similar question, i have a machine about 5months
old running xp media center edition. It has 4gb ram, an
abit f-l90 motherboard and a pentium 3.2ghz dual core.
It was screaming fast when i first set it up, but now it
takes about 20-30 minutes to startup windows and when
it does start, programs run very slow and windows will
routinely just lock up to the point where the machine isn't
really useable anymore (especially as a piece of home
theater equipment)

I tried a fresh install of xp, and no improvement to the
problem. What on earth could cause this?

If whatever was wrong before was caused by software or malware, you have eliminated that if you re-installed Windows.
However, if you ran a Repair Setup instead, the problem may still be there, because a Repair Setup can't fix problems caused by anything that isn't on the Windows CD (CDs in this case, if it's an OEM copy of MCE).

Whenever you install Windows from scratch, after Setup is finished you must load the drivers for the mboard, particularly the main chipset drivers, so that Windows has all the proper drivers for and information about your mboard.
E.g. If you don't do that it's quite common for the drive controllers to not be detected correctly, and the hard drives and optical drives won't run as fast as they are able to.

If they are IDE connected, all your hard drives must be connected to 80 wire IDE cables in order to run at their full speed. If you have a DVD drive that is capable of DVD +R or -R 16X or greater it must be connected to an 80 wire data cable if it is IDE connected in order to run at it's full speed.

Check your hard drive with the manufacturer's diagnostics.
See the latter part of response 1 in this:
http://www.computing.net/windows95/...

If you don't have a floppy drive, you can get a CD image diagnostic utility from most hard drive manufacturer's web sites, but obviously you would need to make a burned CD, preferably a CD-R for best compatibilty, on another computer if you need to.

A common thing that can happen with ram that worked fine previously is the ram has developed a poor connection in it's slot(s).
I've had even new modules that needed to have their contacts cleaned.

See response 2 in this - try cleaning the contacts on the ram modules, and making sure the modules are properly seated:
http://www.computing.net/hardware/w...

If this is a laptop, you must remove both its main battery and AC adapter before you do that.