Hi, Windows 7 runs almost like Windows Vista. All the softwares that supported by Vista will work in Windows7 also. The system Requirements is also same. For the O\s, 512 MB of RAM (1 GB Recomended), 64MB of VGA, a Processor of 1.8Ghz. See ya.
Yes you can install Windows 7 in a different partition other than XP, it simply over-writes the MBR(boot loader) so you ll get a boot menu at the boot, with all 7 and XP.