I have a computer motherboard that supports 4gb of ram.

I installed 4gb (2x 2gb sticks) but when it boots up, it only reports 3gb (sometimes it reports 2.5gb sometimes 2.7gb, etc.)

I asked some people and they say you need to remap the bios.

I went into the bios setup and nowhere does it say it has this feature.

Will Ultimate CD help? (sorry, it's late here and I don't have time to burn the cd and explore all the features this late at night.)

You should provide more info, like OS version and SP, exact motherboard model, current BIOS version...

For example, Windows XP 32 bits doesn't "inform" about 4GB of ram. Its a limit of XP 32 bits, and that's true even for a BIOS supporting 4GB.

So if this is your case, let it be.

An additional suggestion would be to go to your motherboard's manufacturer website, search for your exact product (exact motherboard model, specification and revision) and take a look at the last available BIOS version for it. If your current BIOS version is not the same, then maybe you could update your BIOS. Don't do it if you are not completely 100% sure about what you are doing, or you could get a completely useless motherboard. Don't blame anyone else if you do it "the wrong way" and something goes wrong.

You don't need BIOS remapping.

Check out:

http://www.raymond.cc/blog/archives/200 ... gb-memory/

for patched kernels.

Basically, the address space of each process is still around 3GB (1GB taken up by I/O addresses). Windows will take up another 1GB, which means each process still gets around 2GB free RAM. But through PAE, all the physical RAM can be used if you have enough processes (VMs are good candidates).

I am running Windows 7 with a patched kernel, and using all 4GB of my physical RAM. Without the patched kernel, I only get to use 3.2GB physical RAM, which could make the difference between whether I can run 2 versus 3 1GB VMs.

That isn't the safest thing to do to your windows, would recommend against it unless you knew how to repair your computer if it does fail. Save yourself the trouble and just get a 64bit OS.

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~Just StopSpazzing~

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