The software is considered "legacy" or "end-of-life" (EOL). Xilinx allows redistribution for archival purposes, provided no cracked licenses or modified executables are involved.
A: For WebPACK devices, the license is free and can be generated on Xilinx's licensing site. You will need a Xilinx account. Xilinx Ise 9.2 I Software Free Download
A: Yes, but only via the compatibility tweaks described above. The installer is 32-bit and may trigger SmartScreen warnings. The software is considered "legacy" or "end-of-life" (EOL)
A: 14.7 supports newer devices (Spartan-6, Virtex-6) and has better Windows 7/8 compatibility. However, 9.2 is lighter and preferred for older Spartan-3 designs. Xilinx Ise 9.2 I Software Free Download