Hi
I have Celeron 2400MHz with 845E MAX MSI motherboard, I have tried to overclock it, the result was 3200MHz with 133FSB the RAM running now at 266 cause I have lower it throw BIOS from 266 to 200 then begin the overclocking becuse my PC2100 can't go any way after 290, so if I use let say PC2400 or PC2700 will that help me to get much more RAM speed and what is the defult speed for PC2400 & PC2700 .

Thanks in advance

First off make sure your board supports the faster ram and for your next question pc 2400 I believe runs at 333MHZ while pc 2700 runs at 400MHZ.
(ps. You got great results from overclocking, but does it run stable?)

As far as I know pc2400 is 266MHz and PC2700 333 MHz but I can't lay my thumb on it because I'm still stuck to SD Ram so I haven'T had to do much with it!
Check system stability before buying the fast ram. Run a couple of benchmarks like 3dMark2000/2001SE and 2003 (the last only makes sense if you have at least a directx8 compatible card) and try the burnin test from SiSoft Sandra 2003.

At least the 266MHz RAM should work in your board when you can set the ram speed to 133MHz. If you buy new ram get the CL2 version and change the bios settings. It may give a little extra kick.

pc2100 runs at 266 mhz and pc2700 runs at 333 mhz...it's really simple..1 word..google

PC2100 266mhz
PC2400 300mhz
PC2700 333mhz
PC3200 400mhz

MSI 845E tops at 266MHZ PC2100 since 2.4 Celeron is 100mhz x 4, you should not have an problem running 1:1 ratio which ends up at 266mhz range, 5:4 ratio will end up 333mhz which your board may not go.
My old rig was using PC2400 Corsair, it will go to 325mhz but you board may not go that high.

Thanks all, real_cool my motherboard support 533MHz, I have set the settings to use 200Mhz RAM speed instead of 266MHz but after overclocking and using 133FSB * 24multi =3200MHz and the RAM speed become 266MHz which FSB*2 "the defualt RAM speed was approximatly 2.66*FSB Ex. 2.66*100=266MHZ" it perfect untile now, but if I get the PC2700 which 333MHz then I can use 333/2 "166MHz" for FSB, and that will give me 166*24= 3984MHz speed, but that will break the limte of the 533Mhz motherborad but how much speed can the motherboard support after the 533?