Most often, programs are blocked on personal computers automatically when an application tries to do something that violates established security rules. These "police" functions are usually performed by an independent program, and more often even by a whole complex of programs. However, the operating system itself has some means of blocking application applications and individual processes.
To selectively block the launch of programs in the operating system, as a rule, two types of applications are used - antivirus and firewall. There is no tool of the first type in Windows, and the functions of the built-in firewall are limited, therefore, after installation of the operating system, it is most often supplemented with an anti-malware complex, which includes both types of blockers.
However, if you just need to block the application's access to external networks (local or Internet), the built-in Windows 7 firewall will easily cope with the task. This program has several levels of protection that apply to all resident programs, and also allow you to set personal blocking rules for individual applications. To prohibit any program from accessing external networks through the built-in OS firewall, you need to launch the appropriate Control Panel applet. The easiest way to do this is through the search field in the main Windows menu - it is enough to enter three letters "bra" into it, and then select the line "Allow the program to run through Windows Firewall" in the list of results. The applet interface is very simple - you need to find the name of the application in the table and check or uncheck the corresponding checkbox.
You can also prevent the system service from starting through another Windows component. It is also easier to open it using the search query field in the main menu - just enter "slu" into it and press Enter. The window for managing system services that opens contains a long list of them - it includes both running and inactive processes. Any of them can be disabled or enabled through the context menu. There is also a Properties item in this menu, through which you can access a slightly larger set of blocking options. With its help, you can, for example, instead of a complete prohibition set the option "manual start".
