|It is impossible to access 4GB in any 32 bit client version of Windows. Typically you will have about 3.25GB available but it is often less. If the video system is using shared RAM it can be much less. In a 32 bit client OS you have a 4GB physical address space which must be shared with RAM and memory mapped hardware which must have priority. Since hardware and RAM cannot share address space you will inevitably loose access to some RAM. Only a 64 bit OS will be able to use all 4 GB RAM.|
In XP the /PAE switch does nothing useful. It's only purpose is to permit testing of device drivers with the PAE kernel. It does not allow access to more RAM and it does have a small performance penalty. It is really only of use in a server OS. You should remove it.
You should remove the extra 1 GB of RAM. It is not being used and can have a performance penalty.
Please avoid posting in all-caps. On a forum this is bad etiquette and is more difficult to read.