A friend sent me a mail that in order to install windows 8 that my pc needs to support PAE, NX, and SSE2. Pls can anyone tell me what these mean and why they are required to install windows 8?
These are processor requirements
NX means No Execute. It means that your CPU knows how to make parts of memory safer by provent programs from executing code in that part. Your CPU needs to support it and it needs to be enabled. (e.g. you can often turn this off in the BIOS).
SSE2 means that you CPU understands the second set of Streaming SIMD Extensions. These are instructions added to most CPU's since 2001. Windows 8 will use these. If your CPU lacks them then win8 will not be able to run.
PAE is a completely different game. A traditional 32bit CPU uses 32bit addressing. Both internally for data and on the address bus. With 32 bit it can address up to 232 memory addresses (that is 4G). PAE allows the CPU to address up to 36 bits of memory.
Think of it as two squares where you enter a page number. E.g. page "01", "02", .. "99". With only two numbers you can select up to a 100 pages (00 to 99). PEA is like adding a book number in front of it, allowing you to read pages 00 to 99 in book 1, pages 00 to 99 in book 2 etc. (But the books themselves (e.g. the programs) are still limited to 99 pages.
This is an artifact of 32 bit computing. If you have a need to use 4GB or more then please install a 64 bit version.