4 GB RAM not detected in my system

[Lalana]

I am having a problem in motherboard and ram. I just changed my pc A few days ago but I have a concern. The problem is that my motherboard in the bios only detects 3 DDRAM ... 2.93 GB in Windows and cpu-z (1.40). I found out the 4 gigabytes in timer 5 5 5 18 23 (noting that the bars are normally 4 4 4 12). The motherboard has the latest bios available from version. I know that for windows is limited to 3 GB but in general people are 3.2 I 2.93. And I do not understand why Cm 3.07 GB detect that and not 4096 as Cpu-z. So there is not really a problem just wondering why 3 different value? why only 3 Inches detected GB and not 4 as CPUZ? The main thing I am not able to understand that why my 4 GB RAM is not detecting? The following is my config :

Core 2 Duo Proc 6300
Asus P5B motherboard
4 x 1 GB kingston value ram 6400
Windows XP Pro 32bit

[Fragman]

To enable Physical Address Extension (PAE) X86, the following steps would be useful :

1. Open Windows Explorer.
2. On the Tools menu, click Folder Options.
3. On the View tab, click Show hidden files and folders, clear the check box Hide protected files of the operating system, and then click OK. If a warning box appears, click Yes to continue.
4. In the root folder ( eg C: ), locate the Boot.ini file, then delete the read-only attribute.
5. Open the Boot.ini file, and add the / PAE to the ARC path, as shown in the following example for Windows Server 2003, Datacenter Edition:
   
   multi (0) disk (0) rdisk (0) partition (2) \% systemroot% = "Windows Server 2003, Datacenter Edition / EAP
6. On the File menu, click Save.
7. Restore the read-only attribute on the file Boot.ini.
8. For this change to take effect, restart the computer.

I am sure that these steps will help you.

[Quattro]

I would like to tell that to perform the procedure mentioned by the 'Fragman', you must be a member of the Administrators group on the local computer, the appropriate authority or you must have been delegated. If the computer is joined to a domain, members of the Domain Admins group might be able to perform this procedure. One of the best practices for security is to use Run as to perform this procedure. For more information, see the default local groups, Default groups, and Using Run as. To open Windows Explorer, click Start, point to All Programs, point to Accessories, then click Windows Explorer.

[Brunoz]

The 32-bit address space is 2 GB. But the problem is that some bios able to address more than this space by who have nothing of a hack, and correspond to a real problem of file size, image processing. Administrators Genre software, familiar with this problem. It is possible to have an address space> 2GB for example when you have a Dual Core, or 1 (2GB addressable Proc). For those who can not conceive this practice, it must be told why UNIX machines can go up to 12GB of rowing in 32 bits.