Hi am writing a program and want to incorperate expiration date of say 30days after which the user can not use the system until he has purchase full version. thank you

Ok, you told us what you are doing but didn't tell us about the question or problem you are having. If it's a stand-alone PC program that doesn't access your web server then there isn't any full-proof way to accomplish that. Whether you write the date to the registry or to a file someone can always change it on their computer. But if you write it to a database on your server then it will be fairly secure from user tampering. When the program starts, if it is a trial version then query your server to find out the expiration date.

yes its realy correct the trial version is only for the checking bases so that you can know about the software and once you likes the software you have to purchase the full version for the personal use so then you didnt have this kind of problem and you can travelClick Here to various shopes for the software

there are many ways to do so ,
1-If your application has database then store time and date of first run of your application and then check remaining days on load time.
2-If your application has no database then you can store installed date and time in registry of windows. and check remaining days every time you application loads.
3-simple way , just write a textfile , save date and time of first run in encrypted form. and check remaining days every time your application loads.

Best Regards

run in encrypted form

well that is what I'm also having a problem on I tried to crypts mine and it did crypt but the problem was to remove the cryptions so that it can be read easy, you can check on my post and you will see how I wrote mine and where I got problem too.

To answer the question here, you can just simple count your self miliseconds, seconds, minutes, hours, days and you can choose either to count upwards or back wards and then simple refere to it e.g.

Dim Days, Hours, Milisec, Minutes, seconds As Interger

Private Sub Timer1_Tick()

Milisec = Milisec +1
If Milisec = 10 Then
Milisec = 0
seconds = seconds +1
End If

If seconds = 60 Then
seconds = 0
Minutes = Minutes +1
End If

If Minutes = 60 Then
Minutes = 0
Hours = Hours +1
End If

If Hours = 24 Then
Hours = 0
Days = Days +1
End If

If Days = 30 Then
MsgBox("Your trial Has reached and end Please purchase the full version to keep on using this program")
End If

End Sub

Hope this will serve you purpose what you need to do is just save this in files and refer to it.