This is the HKEY_CLASSES_ROOT .3gp registry entry exported from my PC, the default app is Films & TV (Movies & TV). Compare it with your registry. If you want, you could copy the code below, paste it into Notepad, then save as 3gp.reg. Then you can import the registry settings by double-clicking on the 3gp.reg file.
Code:
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\.3gp]
@="WMP11.AssocFile.3GP"
"Content Type"="video/3gpp"
"PerceivedType"="video"
[HKEY_CLASSES_ROOT\.3gp\OpenWithProgids]
"AppX6eg8h5sxqq90pv53845wmnbewywdqq5h"=hex(0):
"AppXk0g4vb8gvt7b93tg50ybcy892pge6jmt"=hex(0):
"AppXqj98qxeaynz6dv4459ayz6bnqxbyaqcs"=hex(0):
"WMP11.AssocFile.3GP"=hex(0):
[HKEY_CLASSES_ROOT\.3gp\ShellEx]
[HKEY_CLASSES_ROOT\.3gp\ShellEx\{BB2E617C-0920-11D1-9A0B-00C04FC2D6C1}]
@="{9DBD2C50-62AD-11D0-B806-00C04FD706EC}"
[HKEY_CLASSES_ROOT\.3gp\ShellEx\{e357fccd-a995-4576-b01f-234630154e96}]
@="{9DBD2C50-62AD-11D0-B806-00C04FD706EC}"
and here is my HKEY_CURRENT_USER .3gp entry.
Code:
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Classes\.3gp]
[HKEY_CURRENT_USER\Software\Classes\.3gp\OpenWithProgids]
"AppXk0g4vb8gvt7b93tg50ybcy892pge6jmt"=hex(0):
"AppX6eg8h5sxqq90pv53845wmnbewywdqq5h"=hex(0):
"AppXqj98qxeaynz6dv4459ayz6bnqxbyaqcs"=hex(0):