When I turn the pc on, usually after a few hours of it being turned off I get this message but I can't see anything in the bios that looks wrong. It's a budget setup built from old bits from my old pc and a few bits I picked up from a car boot sale. The moterboards is an ASUS a7a266. Any ideas why I keep getting this message?
I would have a look at the thermal paste on the CPU ,not to much or to little is the key.Renew it would be good, Check all fans particularly the heat sink and P S U are free from dust build up. Check all connections are firm, remove and reseat is always a good idea. If,as you say that your build is made from bits and pieces got from old PC's and car boot sales then it is highly probable that a part is failing,with mono being the likely suspect. But,as I assume,you like to potter with PC's then you have an interesting challenge.
The core of the pc is my old Asus a7a266 which didn't have any problems previously. One thing that is strange is that the readings in the "speedfan" program look ridiculous, it always gives readings of 127 for something, even when the pc has just been turned on, I'm wondering if some sensors somewhere are getting it wrong.
This happened again this morning at boot up and when I went into "hardware monitor" to investigate there was a red 4.5v next to the +5v which then went up to 4.7. I don't know what this means exactly but could it be that my power supply doesn't have enough oomph after it's been asleep for a while?
Not knowing what your PSU is I couldn't hazard a guess. But I do know that the PSU is a very important component, when I first started building I did not realise how important a PSU was. I appreciate that you have put this PC together from budget parts but it would not hurt to try another PSU.