License expiration and machine date

Question

I am working on an application that is required to be licensed , the license should have an expiration date, I am wondering how to handle the situation where the user changes the machine date to continue using the application.
directions I have so far is :
- create a secret file or a registry entry during the first run of the application.
- uring startup check the machine date is after the stored date
     - yes : update file/entry and start normaly
     - No : date has been modified , show warning and stop
I believe any registry or filesystem activity monitor can catch the place of this file and reset the date? solution might be to encrypt this date?
What could be a good secret place to hide this fie/entry
Is there any better solution?
Thanks

Answer 1

I have/had the 200 message plan that was auto renew monthly.  What they fail to tell you is that there is a maximum limit.  I had 8,900 message units from months of renewals and little usage. I thought nothing of it as long as I kept the account active with the monthly renewal.  First, AT&T texted that they would be doing an autorenewal, as usual, then a few days later I found that the renewal was unsuccessful.  I called as directed by the text to find out why.  Well, renweing would have put me over the 9,000 maximum limit and so their solution was to inactivte my message account, and all of my 8,900 units were taken away due to the inactivation. I argued for 50 minutes to a representative about how ridiculous this was and how AT&T essentially stole about $200 from me by taking away those units. I am still waiting to see how they resolve this issue.  In addition, I found out that there is also a limit of $500 that you may have on a Go Phone account.  If you go over that $500 limit, then the account will not extend, and thereby be inactivated and you lose your account. This is nonsense.  It is my money that I give and they take.  What business is it of theirs how I spend my money or if I use the phone service or features I pay for. It just makes no sense.  I hope that someone from AT&T sees this and responds.  I am kdp123