I think one question NOT addressed to the OP is : WHY? Why are you mandating a huge inconvenience (requiring 12 unique passwords a year) to the end users? Even in a domain environment, it is normally at the maximum every three months, and that is in high end secure facilities that include many database systems, etc. that are also 'synch' with the change over (think Wells Fargo, CitiCorp, etc.). SMBs (small and medium business) should be very security conscious as they have alot more risk to any losses, but honestly passwords are not the main form of 'hacking' if that is the concern. Adding another 'burden' to the daily demands of your employees impacting their performance AND unnecessarily keeping yourself / whomever busy constantly resetting passwords. Lastly, and of biggest concern is, you / whomever is responsible for 'IT' isn't really a qualified IT Administrator, or you / they would realize that this entire thought was bogus, as I would almost guarantee ALL those accounts of those employees (being 'Home Premium edition identifies you probably just bought them 'off the shelf' at CostCo / etc. 'as needed') are using ADMIN accounts, which changing the password again has no effect, as any of them can just go in and change things 'as they want' because THEY are the GODs over the computers not you.
This of course completely IGNORES on EVERY single machine (say 50) each one has its manually enter 'accounts' (say 20 different people, just 'in case' they need to 'get on' the machine, or say to account for all the Managers/Supervisors/etc. that 'need' to be able to get onto ANY system they want) and once they change a password on one machine how does that affect the other 10, 20 or even ALL 50 other PCs? It doesn't, they have to walk around to EVERY single machine and change the password on EACH individual one MANUALLY. So just thinking 50 machines 20 people, you talking 1000 (50x20) changes to be done EVERY 30 days, just so they don't get locked out of each 'system' they potentially could use with the wrong password. To put a 'cost' behind it, lets even cut that in half (500) and IF it takes around 15 minutes of logging in with the 'correct password' then coming up with a new password they 'didn't use before' and isn't a easy to guess password (111111, abcdefg, MyName, etc.) which is still 7500 minutes, or 125 hours, or two whole days EVERY MONTH no one does ANYTHING else but just spending the ENTIRE work day just changing passwords. This ALSO is just the DESKTOP PCs, NOT including any 'programs', databases, etc. you would also have to setup the same way or 'who knows what password in on any of these things anymore?'.
If your above 20 people it is time to consider Domains and at the very least 'outsourcing' a IT solution to your business.