Right - found out this PC (1.8ghz normally) is on a 13.5 multiplier, and was at 133mhz in that BISO thingy/CPU speed. So, I've upped it to 138, so does this mean m machine is now running at 1.863ghz? If it does, I can't tell any difference....

Should there be any warning symptoms from doing this sort of action?

Nah you wouldnt notice any gains at all, especially from the CPU speed, especially the extra 0.063ghz. Like b4 i had a 1.33ghz athlon and i was running 1.0ghz cos the little bugger was producing about 60C of heat, put it down to 1.0ghz, temp went down to 40s and i didnt notice anything at all untill i did my graphics work - processing time slowed right down. Thats the only symptoms u get for overclocking the CPU is the slight gain in heat, but the extra 0.063ghz will just gain a few degrees in temp - if that.

IF u want to overclock it ask urself this what do you want from ur pc: Heavy graphics play games, work, just using internet.... If its the first two then extra CPU speed and ram would be nice but that extra speed i wouldnt bother. The major difference is having more RAM as you know requires to run programs.

Grab at least a gig of ram, ive got 768mb and i think its kinda okish. Not been bothered with mine as its running ok, kept thinking of buying another 512 stick, but not just yet.

It has a gig of ram now, its just I wanted a slightly faster CPU as it in theory should allow me to do this folding thing a little bit quicker. Using maths before it was running at 1.33 x 13.5 = 1.795, so 1.863 is a small improvement.

Generally speaking if you can up the bus speed whilst not effectively running the CPU at a higher clock itself, you will get better overall performance.