operating system will hang using desktop base application

Question

i am using desktop application(Finger print Application) in core i7 desktop computer first generation 2.78 Ghz Processor and 8 GB Ram,this machine will on whole day and night (24 hr) as well as the desktop application (Finger print Application).but this machine get hang after two days or three days.
mean not response the finger print application as well as the do not shutdown the application 
when i press ctrl+alt+ del task manager will show but not working.
any reason
 
plz plz plz,help me any one