Hi, I'm Steve. I'm currently living in Japan, and am not a very good Japanese reader... so appologies for the rather simple questions. I've acquired (someone threw it out! honesly!) a Fujitsu FMV C-600 box. It's got a 1.7 GHZ Celron CPU (SL68C, 1.7GHz/128/400/1.75) and otherwise works (after a little bit of fixing here & there). I'd really like to upgrade the CPU, and have been eyeing a 2.4GHz Celron - though I can't quite make out the actual CPU spec's through the shop window other than it's a 400 MHz FSB. The questions I have are: 1) Can I simlpy plug & play with a similar FSB CPU and expect it to work ? eg. replace the above Celeron 1.7 GHz with a 2.4 GHz version having the same FSB speed. Or do I also need to consider the voltage support, Max. temp. (it's rather hot over here!) 2) The M/b in this case is a Gigabyte OEM version - KBG2 rev. 1.1 ... sadly I've only so far found instances of this m/b in Italy & Germany as well as Japan, and Gigabyte's site makes no mention of it... so I'm stuck when it comes to whether or not I can upgrade. Is the CPU plug & play replacement going to be dictated by the motherboard (assuming FSB is the same) or by the BIOS... ? (as an aside the M/b takes PC2100 memory... if that helps). 3) The Manufacturer's web site, however does say that there are two versions of the same PC produced with a Pentium 4 2A GHz and P4 2.40 GHz processor (though doesn't say what version of processor): http://www.fmworld.net/biz/fmv/product/hard/vdt0211/custom_c.html If FSB is the all important factor, then I could even upgrade to 2.8 GHz... what's your view/opinion... should I take a step into the unknown & simply try it ? Edit: Please use proper thread titles from now on. Thanks.