i changed my memory to 333 mhz now my pc wont start

i went to bios and i changed my memory speed to 333 mhz and my agp thingy tot 128 mb instead of 64 mb ??
when i switch my computer on the only thing i hear is BLEEEEEP

can somebody help ?

greetz

there should be a little jumper on your mobo very close to the cmos battery. switch it for about 15s and then switch it back. this will reset the bios to its default settings and your pc should boot. if you can't find the jumper, just remove the battery for 15s and then reset it