how to upgrade from 32 bit windows to 64 bit

[oddy_grey]

My 8gb ram keeps saying (2.93gb usable) it's a hp windows 8(upgraded) , 32 bit os... How can I upgrade it to a 64 bit OS cause to solve this problem cause am sure that would fix it

 

[Petrossa]

You have to purchase a 64-bit version of Windows and clean install. There is no upgrade from 32-bit to 64-bit available.