Sys_Blocked uses a complex password system to block your PC, so it will be impossible to access the machine without the password.
Sys_Blocked completely encrypts your whole system or just certain areas, if you prefer. To do this, you'll need to establish a password and answers to secret questions that will only be used if you lose your password.
Advanced users won't be able to use their tricks to get around this blocking system, since the process is impossible to cancel from the Windows Task Manager, and will be hidden in the Add/Remove Programs list.
It's in this way that the program improves the original password protection features included in Windows XP.