At MegaCorp we care about your experiences. After your Certified Corporate Extortion is complete a follow up survey will be sent to refine the experience for future users. As a reminder all software is licensed and may be revoked at any time at our discretion. For a limited time only we are offering a Super Liquidation Discount on upgrades before the next Planned Obsolete Upgrade {P.O.U.! It Packs a Punch!️ 🥊}
Semi joking aside you can call the license activation hotline after checking in the Control Panel under System to see if your key is listed there. There are also a few guides to figuring out what made it think its unlicensed. Sometimes there are clock errors that do it, so check if a reboot clears it up and synchronize your time under Date & Time under the control panel. This link discussing using Start > Run > and typing (without quotes) slui.exe or slui.exe 3 or slui.exe 4 to automatically reactivate, reactivate by reentering your license key (see below to get that extracted easily), or reactivate by phone automatically with the key.
https://superuser.com/questions/383260/how-do-i-re-activate-windows-7-after-windows-has-decided-it-is-no-longer-genuine
NirSoft offers a free key extraction tool to do it quickly and graphically just by running the exe file from the zip or installing it fully and double clicking the program icon.
https://www.nirsoft.net/utils/product_cd_key_viewer.html#DownloadLinks
https://www.howtogeek.com/64600/how-to-recover-windows-and-software-keys-from-a-broken-computer/