I have a desktop (Dell E510) that had 3GB memory and I run an x86 and x64 partition. The memory on the properties page of computer showed 3GB installed with no mention of usable for both x86 and x64 partitions. I just installed an additional 1GB of memory and now it shows 4GB installed with 3.62 GB usable. Performance monitor says it is reserved for hardware. I understand that graphics card can share memory but 2 questions arise. Why does it show up now and not when I had 3GB installed? The x86 shows 3.62 usable. I thought the max for x86 was 3.5?