Hi, Enthousiast. Sorry, my English isn't good, and I think I didn't understand very well. Maybe do you intend that I should use a kms emulator, as KMSPico?
If the Windows 7 is in perpetual grace, you can upgrade to Windows 10, but there are issues: 1. Windows 10 does not know any OOBE grace (initial 30 days in Genuine mode), you will be in Notification mode right away (=non-activated with all its restrictions, mostly personalization and watermark). This tool is does not work for Windows 8 and beyond. 2. Windows 10 will not be activated by a digital license/entitlement/Store license. That's because a Windows 7 in trial does not allow for a free HwID. Using Windows Loader (all Win7 SKUs except Enterprise) or a KMS solution like KMS_VL_ALL (only Pro or Enterprise, note that KMSPico and MTK are dead and buried)* will truly activate Windows 7, and Windows 10 will keep the activation after upgrade. Note that activation is hardware-bound. Edit: See post below for KMS-activated Windows.
10 Pro won't get a HWID from a KMS activated win 7 and for enterprise neither, the KMS activation will keep. For 7 Pro KMS activated there needs a specific upgrade step, first upgrading to 10586, before upgrading to the current builds.
Sorry, it's hard to remember all these special requirements. But, if you use KMS, why should you stop? KMS works on any Windows 10.
The HWID is a free gift for the life of the hardware for upgraders ps, he/she never told us what sku he/she is running, only a hint with mentioning the loader.