Vista - mismatched memory in vista 64

have 2x1gb of 800 mhz memory and 2x2gb of 667ghz memory here are the results:

system imformation:
2x2gb 667ghz +2x1gb 800ghz:
Installed Physical Memory (RAM) 6.00 GB
Total Physical Memory avaliable 2.00 GB

2x1gb 800ghz:
Installed Physical Memory (RAM) 2.00GB
Total Physical Memory 2.00

2x2gb 667ghz:
Installed Physical Memory (RAM) 4.00GB
Total Physical Memory 4.00GB

it looks like it doesnt use all the memory if i replace the 2x2gb 667 with 2x2gb 800 will it work?

That's some fast memory. Anyway, if X hz > Y hz then X + Y <= Yhz, unless working with no clock sync at all. Old motherboards supported that, dunno now.

Anyway, reduce the speed of your memory and even more if you're gonna use four slots. Try and see what happens.

Match speed and timmings for better results.

What motherboard(make and model) do you have? You may just need to arrange them properly accross the board for them to be properly recognised.

Example: Slot 0=2gb
Slot 1=1gb
Slot 2=2gb
Slot 3=1gb
Thats how my RAM is arranged and I see all 6gb. Its all the same speed and brand but you should ber able to get it to work...right?

I am mixing Smasung pulled from an HP with ultra ddr2

sorry lol ment mhz. MOBO is xfx 8200 supports up to 8gb. I am gonna buy 4gb of 800 mhz tommorow and i hope it fixes the problem. also i tried adding 2x dell 256mb (lame) to see what happens and this is what i got:

2x1gb 800mhz + 2x256mb 200something mhz= installed 2.5 gb and 2.5gb total physical memory which means it is recognizing it.

so the new memory should work. the 2x1gb is ultra ddr2 and i am either getting the OCZ SLI or Crossair Twinx xms2. which is better any tips?

also when i have 2x1gb + a single 2gb it goes to 4gb and 4gb avaliable. if i add the other 2gb it goes back to 2gb avaliable

By default the slowest RAM sets the bus speed. On some older cheap boards, mixing RAM can cause all sorts of issues. I would match the RAM to your CPU bus and replace two of the sticks with matching RAM. Really, you want 4 identical sticks for best performance and reliability.

its funny because it works fine with 2x1gb and ONE 2GB then when i put the other 2gb it drops the physical memory to 2gb.

What OS and whick CPU and Mother board???

vista 64 and XFX 8200 MOBO. UPDATE: IT TURNS OUT ALL THE MEMORY IS 800MHZ

its like the HP memory doesnt like the ULTRA memory and shuts self off.

one more test: 2x2gb HP ram works 4gb usable then when i add 1x1gb ULTRA drops down to 5 installed and 1 usable

also did BIOS update yesterday

heres the fix FINALLY: The Microsoft System Information (Msinfo32.exe) tool reports the incorrect amount of physical memory in a Windows Server 2008-based or Windows Vista Service Pack 1-based computer that has more than 4 GB of physical memory installed