Windows home basic 32 bit and 64 bit

you can...
but i doubt you'll notice any performance difference
most users only difference is the amount of usable ram (goes from about 3.5 GB to 16BG, which is the limit set by Microsoft, the theoretical limit is much higher)

Thank you very much for your awnser - the computer is reading 4gb ram - the task manager 2.557 - it is a fast laptop, i mainly do lots of photos on the road with it.

Your CPU is probably not 64-bit so yeah...

Can i upgrade the cpu ???

This statement makes no sense. Of course OP's CPU is capable of 64 bit instructions. 99.5% of CPUs produced since AMD 64 five years ago are 64 bit capable.

i think it is its an Intel Pentium 4 and i sent it back to HP in 2007 - they did put a new hard drive and i think a different prossesor because when you open the task manager it shows 2 meters at the top and is supposed to only have one - i think it is running 64bit as its reading Vista service pack 2 and says 32 bit which might be a glitch then again i could be wrong

All Pentium 4 CPUs are 64 bit. Read argus86 post. Ignore whooleo's post. Before installing a 64 bit operating system, chck the laptop's online product page for 64 bit drivers. As argus86 stated, you wouldn't notice much difference with that system.