my toshiba satellite notebook can accept up to 4gb ram. So i bought 2x2gb. When i install both ram cards the windows doesnt starts. when i install only one ram card then it works fine. When i install both in bios setup display me that there are only 3gb ram and not 4. The cards and slots are ok., i m sure about that. Any help?

Unfortunately, 32 bit machines can only handle up to 3 gigs of mem. <approximately> Oh, well.

hm, but when i installed the 4 gb the windows must be start and the system recognise only 3gb, but the windows dont start at all

Hey, same here i have 4gb installed and only 3gb is showing

Difference with mine is that i have 2x1gb and 1x2gb, yeah i know thats not cool... especially since they're not branded the same
i'm getting another 2x2gb of the same this week

is it seriously true that 32-bit OSs won't handle 6GB?
my motherboards supposed to handle up to 8GB but should i get the 64-bit os, will that handle the 6GB?

The range of integer values that can be stored in 32 bits is 0 through 4,294,967,295 or −2,147,483,648 through 2,147,483,647 using two's complement encoding. Hence, a processor with 32-bit memory addresses can directly access 4 GB of byte-addressable memory. Some of the 4 gigs is reserved.

Cite

use /pae and /3gb in the boot.ini to make windows make better use of the 4gb

how can i do this ?

OK

looks like i'm finally ordering my (free) copy of winVISTA Home Premium 64-bit
Goddamn Postage Charges!!!

The range of integer values that can be stored in 32 bits is 0 through 4,294,967,295 or −2,147,483,648 through 2,147,483,647 using two's complement encoding. Hence, a processor with 32-bit memory addresses can directly access 4 GB of byte-addressable memory. Some of the 4 gigs is reserved.

Cite

This is true, as the flat model memory addressing of 86x is set at 2^32, = 4,294,967,295. Does this mean that the 64x architecture can handle up to 2^64, or 18,446,744,073,709,551,616, (18 exabytes, or around 18 billion gigabytes)? I realize that motherboards cannot handle this much, but it is fascinating to contemplate, even more so considering Moore's Law I have also heard of intel having already developed a processor with 80+cores. What kind of computers do you think we will have in the near future? :) A further note: I have seen many people waste their money purchasing a 64x OS to be able to run 8gigs of memory. I call it a waste because the average user will not need this much, unless setting up a server or using intensive applications such as major video editing. More importantly, There will not be a drastic difference in switching from 86x to 64x with a gain of .5 to 1gig of memory. Saying that, windows server 2008 will be the last 32 bit operating system to be offered by microsoft, and thus it is inevitable that we will make the transition. But by then I am sure the support will be vastly increased proportional to the amount of the people using it at that time.