Collect some uncommon operating materials in Windows

Q: How can I add environment variables through programming?

A: Windows provides the setenvironmentvariable API function. However, this function can only modify the environment variables of the current process, rather than other processes and system variables. To modify the environment variable of the system, you need to modify the items in the registry system/CurrentControlSet/control/Session Manager/environment, and then send the wm_settingchange message. For example:

Rootkey: = HKEY_LOCAL_MACHINE;
Openkey ('System/CurrentControlSet/control/session' +
'Manager/environment ', false );
Writestring (name, value );
Sendmessagetimeout (hwnd_broadcast, wm_settingchange, 0, lparam
(Pchar ('enable'), smto_abortifhung, 5000, RV );