111-1111111

Windows 95 product key. Used during installation to certify that the copy of the OS is the original.

"Why 111-1111111 is a valid Windows 95 key?"
"Windows 95 determines a key valid if:
- The first 3 characters must not be equal to 333, 444, 555, 666, 777, 888 or 999.
- The last 7 characters must all be numbers from 0-8.
- The sum of the last 7 numbers must be divisible by 7 with no remainder.
- The fourth character is unchecked."