Hi people,

as far as I understood x86 assembly, I can use EAX,EBX,ECX,EDX and also ESI and EDI for general purpose stuff. So is that 6 registers all that are available ? I would like to have more to minimize memory access sometimes...

I know that there are EBP, ESP and EIP. But I think as long as I use subroutines in my code these can't be used for general purpose. Is that right ? Or in which case I could use these also ?

right.

EIP is not general-purpose register, and you can't directly access it.
ESP is pointer to top of stack, when it's value is changed "push", "call", "ret" etc. instructions won't work
EBP is used as frame pointer in procedures, you can use it yourself, but not inside "proc" - declared procedure. i suggest not to use it unless you know what you are doing.

The thread is in 'Windows' section so remember that you have to preserve EBX, EDI and ESI. Push them, use in any way you want and pop them to return their values.

Reverend: you forgot EBP... there are so called "leaf" procs which don't have stack frame even in "good" win32 code