Windows 7 Product Key Not Working [upd] Page

| Error Code | Meaning | |------------|---------| | | Key is for an older version of Windows; requires upgrade installation path | | 0xC004F063 | BIOS missing or invalid SLIC table (OEM activation failure) | | 0xC004C003 | Activation server determined key is blocked | | 0xC004E003 | Product key already used on another PC (exceeded activation limit) | | 0x80072F8F | Date/time incorrect or activation server unreachable |

It is easy to mistype the 25-character code. Check for common mix-ups like "B" instead of "8" or "O" instead of "0". windows 7 product key not working