When placing two slots of 1gb ram my computer won't start

what u mean compatible? if u mean u want to change your ms 6540 to Asus P5S800-VM, then i tell u it cannot be done.
first thing that u look when to change mainboard is SOCKET type... ms 6540 have socket type 478 and asus p5s800-vm have socket type LGA775. thats mean your old processor cannot be use in asus. socket 478 is older than LGA775.
So if u want to change your mainboard for ASUS P5S800-vm, then u need to change your processor to... about RAM socket and VGA socket, ms 6540 have same type with ASUS P5S800 (DDR400) so u dont need to change your RAM and VGA (if u use external VGA)
hope this useful, regards.

Yes it can support 1GB ram. Max capacity up to 4GB of ram, meaning 1GB each on each slot. Make sure that the memory that you will be installing are either DDR400, DDR333 or DDR266. It could be the RAM is faulty if the one you bought is the DDR's that I mentioned

The black and blue slots are to indicate where paired sets of identical DIMMs should be inserted. So one pair would use the blue slots and the other pair would use the black. It's possible that your motherboard doesn't fully support this RAM type but you would only be able to find that information at the Motherboard maker's website. Hopefully they still have BIOS updates for that motherboard posted online so you can update it. Sometimes all you need is an update to the BIOS to support newer processors or memory.

I’m happy to help further over the phone at https://www.6ya.com/expert/matt_7e951e081251ffbc

hi

your motherboard supports following RAM only

Note: PC2100/PC1600 up to 3 DIMMs; PC3200/PC2700 up to 2 DIMMs; 1GB PC3200/2700 with 32 DDR chips up to 1 DIMM only)

That board type does not show on the ASUS web site. I think that your problem may be incompatibility of the RAM with the board specs. Placing faster RAM on the board will not make it go faster.

i think you system also show the beep.
when this problem occured.
your ram may not be compatible for your system.
to solve the problem use this help
1-change the RAM
2-Ram insert into another Slots
3-may be 1 gb RAM not support to your system.

Check the RAM in another machine if it worked then the RAM slot might have some problem....

Some motherboards require that you install the memory in matched pairs. That could explain why they won't work together.

When you put the 1 GB in alone, what slot did you put it in?
I would suggest the blue A1 slot (closest to the CPU).

It may be that you have a bad memory module.
You could try the Windows Memory Diagnostic:
http://oca.microsoft.com/en/windiag.asp

You may also be interested in the motherboard's manual:
http://dlcdnet.asus.com/pub/ASUS/mb/socket775/P5GL-MX/e2222_p5gl-mx.pdf

More people should complain with Asus support. Checking Asus forums, you'll find there's an obvious problem with a PCI-E video addon + 2 used memory slots. In my case, I had 2Gb (1 + 1), mb with bios version 1104, and it worked fine; when I installed a new PCI-E card, the system was very... very sluggish. Now I have uninstalled 1 memory, I'm using only 1Gb of RAM with the PCI-E card, and it's working well.

Again: checking Asus forum, this is a reported problem, and a bios bug... Asus should release a new bios version, but they seem not to bother, as this is a relatively "old' mb...

Is it ECC memory? What did you do to get one stick working? How many beeps? Do you have the owner's manual for the unit? Did you try to escape to BIOS to check settings? Here is what the ASUS site gives for memory specs, but the onwer's manual should have more info on upgrading memory: Memory 2 x 184-pin DIMM Sockets support max. 2GB PC3200/2700/2100 non-ECC DDR SDRAM memory If you don't have the manual you can get it here: http://dlsvr03.asus.com/pub/ASUS/mb/socket775/P5S800-VM/e2419_p5s800-vm.pdf