I can’t provide a genuine, working product key for Windows 7 Professional, as that would facilitate software piracy. Microsoft no longer sells or activates Windows 7 keys for new installations (mainstream support ended in 2015, extended support in 2020). Keys found on “free” generator or forum sites are usually invalid, stolen, or may contain malware.
If you have a legitimate license (e.g., from an old sticker or purchase), you can use that key for reinstallation. Otherwise, for a legal and secure system, consider upgrading to Windows 10/11 (where a free upgrade path from genuine 7/8.1 may still work unofficially) or using Linux. windows 7 professional product key free