没有什么比最终能够在你的计算机上执行一次大的升级更令人敬畏的感觉了，但是当你的系统拒绝使用整个升级时，你该怎么办呢？今天的超级用户问答帖子回答了一位沮丧的读者的问题。

今天的问答环节是由SuperUser提供的，SuperUser是Stack Exchange的一个分支，是一个由社区驱动的问答网站分组。

照片由丹尼尔·迪翁（Flickr）提供。

问题

超级用户读者Meow主席想知道为什么他的Windows 7系统没有使用计算机上所有可用的RAM：

I have Windows 7 Home Premium (64-bit) installed on my computer and the motherboard is able to handle up to 32 GB of RAM. I recently upgraded my computer to 20 GB of RAM, but the operating system says that only 16 GB of the 20 GB I installed is usable.

I have four slots on the motherboard. I installed two 8 GB sticks of RAM closest to the CPU and two 2 GB sticks of RAM in the remaining slots. I made sure that the RAM sticks are the same (DDR3, 1600 MHz). Just in case it matters, I also installed a GTX 770 GPU with 2 GB of memory. Here is a list of the specificati*** for my motherboard: P8P67_LE Motherboard (Asus).

What am I doing wrong? Why am I seeing this issue in my computer’s Control Panel?

为什么Meow主席的Windows7系统不能使用其他4GB内存？

答案

超级用户贡献者加拿大卢克为我们提供了答案：

Windows 7 Home Premium supports up to 16 GB of RAM. That is why only part of what you have installed is showing as usable even though your computer supports the extra RAM and does detect it. It is a licensing issue in Windows 7 that only allows it to use 16 GB of RAM. You can view the memory limits for various versi*** of Windows and Windows Server releases via the link below:

Physical Memory Limits for Windows and Windows Server Releases Note: This link is set to the Windows 7 portion of the support page.

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