hello:
I would like to ask:


-can I install a 32bit OS in a 64bit machine? (windows)
-can I run 16bit aplications in 64bit machines? (real mode)
-can I run 32bit applications on 64bit machines? (with 64 windowsOS)

in general I would like to know about all the compatibilities with

16bit-32bit-64bit

thank's.

-yes
-yes, but only with a 32-bit OS
-yes

Hmm... Check out "WOW64" on www.msdn.microsoft.com, main Windows resource for programmers.

AlexP, you need to remove the "," from your link.

1). Yes. I run Vista SP1 32-bit (Home Premium) on my AMD64x2.
2). It runs 16-bit DOS programs fine (either under Vista or real DOS booted from CD).
3). Never tried (as 64-bit Windows ain't free), but yes, you supposedly can. Of course, as mentioned, you can't run 16-bit stuff (even something like DJGPP which uses a 16-bit stub) on a 64-bit OS due to no V86 mode under long mode.

You might also have a fairly hard time finding 64-bit drivers for your 64-bit OS since (at least Windows) they have to be completely rewritten from scratch. So, if you're interested in compatibility (e.g. 16-bit stuff like DOS), you'd better dual boot. Otherwise, you probably won't care (except if you can't find drivers for your peripherals, heh).

The sensible solution might? be to dual boot any ol' Win32 (e.g. XP) and something else like Ubuntu 64-bit edition. Or you can run a 64-bit OS (e.g. Menuet64) under QEMU on Vista 32-bit.