Windows 11 has dropped support for several antiquated components that ISE 14.7 relies on:
If you are designing a new product, do not start with ISE. AMD's supports 7-series and newer FPGAs (Artix, Kintex, Virtex-7). For Spartan-6 specifically, consider the open-source SymbiFlow / nextpnr toolchain—it runs natively on Windows 11 and is gaining production trust. xilinx ise for windows 11
The good news? The better news? With a few tweaks, it can run reliably. Windows 11 has dropped support for several antiquated