200 > 266 Fsb

Im running a 900MHz Thunderbird @ 100 * 10.5 > 1050MHZ, i ran it @ 266FSB as appose to 200FSB and lowered the multiplier and everything wa fine. I just want to check if using a 266 FSB will b too much for my CPU to handle. The temperatures where about 40 idle.

Not a problem... If u running stable and ur system has the 1/4 divider ur 100% fine

1/4 divider????

Your MoBo has the KT133A chipset that will allow it to run at 133MHz/266FSB or more. The chip generaly shouldnt have a problem running at the increased FSB. My CPU was a 100MHz/200FSB variant but is happily running at 143MHz/286FSB.

Read up on the basics here for BIOS explanations. 1/4 Divider pertains to the PCI Bus Speed. It needs to run at 33MHz to run at spec. 133MHz X 1/4 = 33MHz but if your MoBo does not have it it'll be more like 133MHz X 1/3 = 44MHz which is not really suitable for PCI components. All KT133A chipsets have this so don't worry about it.