The modern flregkey.reg file you find under 'my account' > 'unlock products' only unlocks FL Studio versions 9 to 12.
To register FL Studio version 7, you need to use a legacy registration code.
We can not provide registration files for FL Studio programs version 8 and version 6 or older anymore.
Make sure to be signed in to your 'my account' page. Than click this link to download your legacy registration key: Unlock it with a new legacy registration code.
Please check your 'my licenses' section if you own an older FL Studio program, or post a support ticket if you have a new registration, but want to register an old program for some reason.
https://support.image-line.com/member/regcode_legacy.php
!! Attention, you need to be signed in to your 'my account' and have an official registration bought & active to use the above link.
Run this different flregkey.reg file to unlock FL Studio version 7.
The legacy code unlocks versions 7 to 10 (except version 8 where no registration is available anymore)
Versions 6 and older can not be registered using a downloadable key anymore.
Need an old FL Studio installer? Look at this article:
Where can I find older Fruityloops / FL Studio installers?