Ive just installed some more memory on my computer, and bios doesnt let me change it from 266 to 400mhz?

Question

Ive just removed a PC3200 256MB 400Mhz DDR SDRAM from my computer and added a PC3200 512MB 400Mhz DDR SDRAM, im not sure if it was running a 400Mhz before but now, when i check the RAM in BIOS, it says its running at 266Mhz and wont let me change it? Would could i do about that, heres my PC info via PCPitstop:
System OS Windows XP Home SP2
System OS Install Date 8/31/2005 7:32:31 PM
System Make Dell Computer Corporation
System Model Dimension 2400
System Serial Number F9H1B81
Main Board Make Dell Computer Corp.
Main Board Model 0F5949
Main Board Version A01
Main Board BIOS Dell Computer Corporation Phoenix ROM BIOS PLUS Version 1.10 A05 DELL - 7 20031202
Processor Description Intel Celeron
Processor Clock Speed 2400 Mhz
Graphics Description NVIDIA GeForce FX 5200
Memory Installed 1024 MBs
Memory Slots 2 slots
Memory Configuration 512+512;DIMM SDRAM Synchronous
Drive Name (C)
Drive Size (C) 34828 MBs
Drive Format (C) NTFS
Drive Name (D)
Drive Size (D) 78528 MBs
Drive Format (D) NTFS
DVD-RW Model SONY DVD RW DRU-530A
DVD-RW Read Speed 16620 KB/sec (94X)
DVD-RW Write Speed 16620 KB/sec (94X)
Monitor Model COMPAQ 21063
Monitor Resolution 1600 x 1200 pixels
Monitor Screen Size 14 x 10.5 inches
17.5 inches (diagonal)
Monitor Manufacture Date November 2003
Monitor Serial Number 1282310645

Answer 1

i agree with that guy. and also if you 'clock' your ram buy a heatsink also.

Answer 2

Here are the specs for your computer http://support.dell.com/support/edocs/systems/dim2400/en/sm_en/specs.htm . It only takes PC2100 (266-MHz) or PC2700 (333-MHz) DDR SDRAM (non-ECC) . I don't know of any BIOS that shows how fast your RAM is. You can go to http://www.belarc.com and download the free Belarc Advisor which will give you greater detail of what you have.

Answer 3

nicely the indisputable fact which you're checking your no longer consumer-friendly rigidity for a memory replace ought to tell you something! Your C rigidity would not have a rattling component to do with the quantity of memory you have!

Answer 4

if there's another RAM stick that's 266 then it automatically downclocks the second 400 stick to 266