computer freezes

[chrisrob]

Not sure why it's doing it but my desktop machine frequently freezes requiring a reboot. It's nearly 6 years old but it was state of the art then - 2.8MHz,1 Gb memory, 80Gb + 150Gb hard drives etc and I don't want to replace it.
In the last few years I have added a water cooler on the cpu and extra case fans to create a proper flow path for air - this cured an overheating problem it was prone to - and I keep it vacuumed out and ensure the fans turn freely.
The Windows XP (service pack 3) is updated regularly as are the anti virus (AVG), firewall (Commodo), anti spyware (Spybot), etc.
I have run various analysis programs but cannot find any software or hardware faults.
Any suggestions what I should try next?

[chrisrob]

Should also have said it has high quality graphics and sound cards although we're not into high power games. It freezes more frequently when my wife's using it - usually reading and writing emails - she uses IE7, hotmail and Word. (I use Firefox, Gmail and Open Office - but still get occasional freezing).

[beso]

The age of the machine plus the previous overheating problems is likely to have resulted in substantially degraded electrolytic capacitors.

With old capacitors, heavy current demand surges from the CPU result in voltage brownout and will cause freezes.

The caps don't cost a lot but it can be tricky to get the old ones out because of the plated-through holes in the circuit board. You need a reasonably powerful soldering iron, good quality solder wick and considerable skill and patience.

[ACtheTROLL]

you clean the hardware ... but what about the software...?
It's just as prone to muck..

NTFS likes 20-25% free space.
lots of RAM results in a huge swap file
which older discs can't write fast enough
and the swapfile likes to be in contiguous space
on older machines ... none of the above tends to happen ... and your machine slows down

also people tend to collect photos and music ... which bloats the FAT or MFT .... it's not the disc space that's the issue it's the database listing the start location of all the files
1 x 4Gb file has only 1 entry in the table
4Gb of photos could have 30,000 ... and searching that lot takes time - even though 4Gb could be less than 1% of the total disc space

install this
http://www.ccleaner.com/download
run with the defaults
then run chkdsk or the windows error checker tool (disc properties)
finally defrag the disk.

and that's about all you can do

except
ideally you should do a clean re-install of xp ... I do mine about 12-18 months
you sound like a bit of an enthusiast ... and frankly we are a bl@@dy nusance ...

adding software tweaking registry entries... just seeing if ...

It's all good clean fun ... but it does nothing for the machine ... all those helpful mods tend to sit in the U bend and clog up the works

[rojash]

I'm guessing you mean 2.8 GHz (unless it runs at around 2/3 the speed of the original 1983 IBM PC) :-)

[chrisrob]

Apologies Rojash, you're right.
Thanks AC, I have run ccleaner & use Advanced System Care.
Photos & Music are stored on larger disc (or removable drives) so there's about 40% clear disc space on C: drive - but there are probably old unwanted programs still lurking to be removed.