Win7 system computer why 8g memory is only available 4g ​​

win7 system computer why 8g memory is only 4g available, why is the computer available memory lower than the actual? I believe this is a lot of users' questions, after installing win7 system, found that the computer's configuration above 8G memory is only displayed as 4G The memory is available, what is going on? What is the 4G memory? Where is the following small series to analyze the specific reasons!

win7 system is divided into 32 bits and 64-bit system, many friends who are not familiar with the computer may not know what is the difference between win732 and 64-bit? Recommended: win7 system 32-bit and 64-bit difference

For win7 32-bit system, The maximum memory it can support is 2 to the 32nd power = 4294967296 (bit) = 4 (GB) or so. Your memory can only support up to 4G of memory, so regardless of your memory size is greater than 4G, it can only detect about 4G of available memory. If your win7 system is 64-bit, then it's not the same, it can support more than 100 million GB of memory. So when your memory is more than 4G, you can only use the win7 64-bit system to fully utilize the computer memory.

Nowadays, most applications are compatible with 64-bit systems. On the contrary, some applications must be supported by 64 bits. Of course, as for the number of digits of the win7 system, you can make your own decision. I believe that after the above sharing, everyone will no longer be 8G memory computer can only identify 4G memory is doubtful!