Not sure if this is accurate but for Windows Xp the max amount of ram you can have at once which I'm sure is currently impossible is 128GB of ram.
Wrong.
99% of all installations of Windows XP are 32-bit. The other 1% is 64-bit XP which, is quite broken as far as I know.
Yes, there are 32-bit versions for Vista and 7 too and 64-bit versions.
The difference is the amount of RAM they recognize. 32-bit or x86 versions of Operating Systems can only recognize up to 3.5 GB of RAM. 64-bit or x64 versions can recognize somewhere to millions of gigabytes of RAM I think but I'm definitely not correct.
Lol my RAM is $35 per GB and thats on Newegg and the cheapest company I could find.
Bad sign FYI.
I currently have 4GB but for my next build I'm going to have 6GB.
My laptop has 1.25GB, for some reason 256MB is built in.