вот как у меня выглядит .reg файл
firefox.reg
PHP код:

REGEDIT4
[HKEY_CLASSES_ROOTFirefoxHTML]
@="Firefox Document"
[HKEY_CLASSES_ROOTFirefoxHTMLDefaultIcon]
@="C:\\Program Files\\Mozilla Firefox\\firefox.exe,1"
[HKEY_CLASSES_ROOTFirefoxHTMLshell]
[HKEY_CLASSES_ROOTFirefoxHTMLshellopen]
[HKEY_CLASSES_ROOTFirefoxHTMLshellopencommand]
@="\"C:\\Program Files\\Mozilla Firefox\\firefox.exe\" -requestPending -osint -url \"%1\""
[HKEY_CLASSES_ROOTFirefoxURL]
@="Firefox URL"
[HKEY_CLASSES_ROOTFirefoxURLDefaultIcon]
@="C:\\Program Files\\Mozilla Firefox\\firefox.exe,1"
[HKEY_CLASSES_ROOTFirefoxURLshell]
[HKEY_CLASSES_ROOTFirefoxURLshellopen]
[HKEY_CLASSES_ROOTFirefoxURLshellopencommand]
@="\"C:\\Program Files\\Mozilla Firefox\\firefox.exe\" -requestPending -osint -url \"%1\""
[HKEY_CLASSES_ROOThtm#_Toc84246028_auto_file]
@=""
[HKEY_CLASSES_ROOThtm#_Toc84246028_auto_file\DefaultIcon]
@=""
[HKEY_CLASSES_ROOThtm#_Toc84246028_auto_file\shell]
[HKEY_CLASSES_ROOThtm#_Toc84246028_auto_file\shell\open]
[HKEY_CLASSES_ROOThtm#_Toc84246028_auto_file\shell\open\command]
@="\"C:\\Program Files\\Mozilla Firefox\\firefox.exe\" -requestPending -osint -url \"%1\""
[HKEY_CLASSES_ROOThttp]
@="URL:Протокол HTTP"
[HKEY_CLASSES_ROOThttpDefaultIcon]
@="C:\\Program Files\\Mozilla Firefox\\firefox.exe,1"
[HKEY_CLASSES_ROOThttpshell]
[HKEY_CLASSES_ROOThttpshellopen]
[HKEY_CLASSES_ROOThttpshellopencommand]
@="\"C:\\Program Files\\Mozilla Firefox\\firefox.exe\" -requestPending -osint -url \"%1\""
[HKEY_CLASSES_ROOThttps]
@="URL:Протокол HTTPS"
[HKEY_CLASSES_ROOThttpsDefaultIcon]
@="C:\\Program Files\\Mozilla Firefox\\firefox.exe,1"
[HKEY_CLASSES_ROOThttpsshell]
[HKEY_CLASSES_ROOThttpsshellopen]
[HKEY_CLASSES_ROOThttpsshellopencommand]
@="\"C:\\Program Files\\Mozilla Firefox\\firefox.exe\" -requestPending -osint -url \"%1\""
[HKEY_CLASSES_ROOTru/_auto_file]
@=""
[HKEY_CLASSES_ROOTru/_auto_fileDefaultIcon]
@=""
[HKEY_CLASSES_ROOTru/_auto_fileshell]
[HKEY_CLASSES_ROOTru/_auto_fileshellopen]
[HKEY_CLASSES_ROOTru/_auto_fileshellopencommand]
@="\"C:\\Program Files\\Mozilla Firefox\\firefox.exe\" -requestPending -osint -url \"%1\""
[HKEY_CLASSES_ROOT.htm]
@="FirefoxHTML"
[HKEY_CLASSES_ROOT.htm#_Toc84246028]
@="htm#_Toc84246028_auto_file"
[HKEY_CLASSES_ROOT.html]
@="FirefoxHTML"
[HKEY_CLASSES_ROOT.ru/]
@="ru/_auto_file"
[HKEY_CLASSES_ROOT.shtml]
@="FirefoxHTML"
[HKEY_CLASSES_ROOT.xht]
@="FirefoxHTML"
[HKEY_CLASSES_ROOT.xhtml]
@="FirefoxHTML"