0

I am experimenting with software copy protection ideas and now I have the following problem.

I have a trial version of my application. Trial data are stored in a certain file and also in some certain registry keys. Of course I know that user can break this trial protection by using some registry and file monitoring and backup tools but I want at least protect against some simple hacks like date-time changes and using Windows System Restore.

The problem is that Windows System Restore wipes out all my application files and also the trial data. I know that System Restore does not affect User's documents folder but I not want to store the trial datafile there, because it is too obvious.

Is there any way I can stop System Restore to remove my trial data file?

JustAMartin
  • 13,165
  • 18
  • 99
  • 183

2 Answers2

1

I know this is old but since the selected answer doesn't answer the question asked I figured I'd add my answer for anyone else that ends up here.

To make System Restore ignore files add a REG_MULTI_SZ registry value to the following key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\BackupRestore\FilesNotToBackup

Environment variable and wild can be used. To include subdirectories add " /s" to the end. For example to add everything in c:\temp using reg.exe from the command line 

reg add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\BackupRestore\FilesNotToBackup /v Temp /t REG_MULTI_SZ /d "c:\temp\* /s"
jbriggs
  • 353
  • 2
  • 10
1

Why not store it in the user's doc application folder?

  • Encrypt the content in the file
  • When the file is gone, trial is over

Application folder

http://msdn.microsoft.com/en-us/library/bb425869.aspx

Security through obscurity

http://en.wikipedia.org/wiki/Security_through_obscurity

Other option is the use of the application settings

Best practice to save application settings in a Windows Forms Application

Community
  • 1
  • 1
Ralf de Kleine
  • 11,464
  • 5
  • 45
  • 87
  • That would be too obvious: user will look in the docs folder and see that there is some weird file. – JustAMartin Apr 06 '11 at 09:44
  • Why is it relevant that the user notices strange files? – Ralf de Kleine Apr 06 '11 at 10:42
  • Because users sometimes delete strange files in their data folders, especially because there are lots of viruses as .exe, .inf, .jpg.exe, fake recycle bin files. I know many people, who delete from their flash memory sticks everything that they did not write there themselves, and some people do the same for their documents folder. – JustAMartin Apr 09 '11 at 11:42