A method for preventing continued use of a protected computer program in a data processing system beyond a designated test period, said data processing system including a valid password, date stamp, and timer, said method comprising the steps of:
- (a) providing an initial time setting for said timer at the time of installation of said protected computer program in said data processing system;
- (b) making a determination as to whether said valid password has been entered;
- (c) continuing with step (d) if said valid password has not been entered;
- (d) making a determination as to whether said date stamp has been created;
- (e) continuing with step (i) said date stamp has been created;
- (f) incrementing said timer to measure cumulative elapsed time of said data processing system while active:
- (f) incrementing said timer to measure cumulative elapsed time of said data processing system while active:
- (h) creating said date stamp if said predetermined value has been reached;
- (i) making a determination as to whether the current date exceeds the date associated with said date stamp by an amount equal to or greater than said test period;
- and
- (j) if the result of making said determination in step (i) is true, causing the protected computer program to be disabled.