Termux runs on the Linux kernel (via Android’s underlying kernel). Windows 7 requires an x86 (Intel/AMD) CPU and BIOS/UEFI. Most Android devices use ARM64 processors. Therefore, to run Windows 7, you must emulate an x86 environment inside Termux.
: Windows 7 needs a BIOS or UEFI firmware, a traditional PC architecture, and a compatible processor, which most mobile devices don't offer. install windows 7 on termux