REGEDIT4

[HKEY_CLASSES_ROOT\thunderlink]
@="URL:thunderlink Protocol"
"URL Protocol"=""

[HKEY_CLASSES_ROOT\thunderlink\shell]

[HKEY_CLASSES_ROOT\thunderlink\shell\open]

[HKEY_CLASSES_ROOT\thunderlink\shell\open\command]
@="\"C:\\Program Files (x86)\\Mozilla Thunderbird\\thunderbird.exe\" -thunderlink \"%1\""