vDos is largely freeware, even open source. A small part of its proprietary code is however excluded from the source files (of no interest if you don’t plan to modify and rebuild vDos). vDos will check if the PC is joined to a domain, or a network drive is addressed. The About popup/nag is then displayed at startup. That eventual nag can be clicked away, without consequences for vDos’ functionality. If vDos isn’t used that often, this shouldn’t pose a real obstacle. So vDos is also sort of mild nagware for some targeted business users. A registration or donation would of course still be appreciated, even if the nag doesn’t apply.
That nag won't show up anymore. A good feeling you'll contribute to rewarding the countless hours invested in vDos, further development and support, keep vDos nag-free for most (99+%) users? You'll be informed of new versions. Some two weeks after the initial release, so eventually reported bugs will be fixed. Registered users however generally don't care about new vDos versions. The current one does the job, if it isn't broken… I could be more open to your specific issues or wishes, and supply an intermediate pre-release to address those.
After filling out the registration form, you’ll receive a mail with an invoice and license file (if paid directly by Stripe). The license file is to be copied to the vDos.exe directory. That’s it, no further activation procedures or online validations. Transferring a registered vDos to other/new systems, remains a copy of some files (plus one).
Registration is lifetime and remains valid for any new versions. If I would decide to change this policy, it won’t involve existing registrations. vDos can be registered in two editions:
User name: € 35 per user name.
The Windows user name has to be (one of) the user name(s) defined in the license file.

Networked: € 150.
The number of users is unlimited, as long the PC’s are joined to the registered domain or that network drive is addressed.

The required user name or network ID are shown in the nag, System Menu - About… in a framed vDos window, or issuing the ABOUT command at the vDos/DOS command prompt.
You can (should!) evaluate vDos for as long you feel needed to be confident it will fulfill your requirements. A vDos license can’t be revoked since there’s no online validation. It will remain valid for the registered (future) edition it applies to. So you would have to convince me vDos suddenly doesn’t function anymore for you…

This could change with a next vDos release. Any vDos usage requiring an online activation and validation. So I can actually disable your vDos copy, and do a refund. This would of course bring a burden/cost to other (not already registered) vDos users.
Money back guarantee?
Is registration needed?
What will it bring?
How does it work?
What about new versions?