To run AutoCAD 2012 smoothly on Windows XP or Windows 7 (32-bit), your hardware should meet these minimums: Operating System:
32-bit applications on Windows can address at most 2GB (or 3GB with a special boot switch) of RAM. Large, complex drawings will cause "Out of Memory" errors quickly. Modern 64-bit AutoCAD can use effectively unlimited RAM. Autodesk AutoCAD 2012 Portable Compalite -XP-WIN7 32 Bit-