[Windows Mobile Development and Hacking General] xvx45:
You need to make change in registry :

(from Diamond Youtube oem pack rgu)

[HKEY_CURRENT_USER\ControlPanel\Keybd\ChangeBackVKeyCode]
"HTCYOUTUBE"=dword:0000001B

[HKEY_LOCAL_MACHINE\SOFTWARE\HTC\YouTube]
"PlayBufferTime"=dword:0000005A
"DefaultBufferTime"=dword:0000000F
"HTTPTimeOut"=dword:00015F90
"CreateConnectBySD"=dword:00000001
"BandWidth"=dword:00000000
"GuaranteedBandWidth"=dword:00000000
"MaxBandWidth"=dword:00000000
"FilePath"="\\"
"ProxyName"=""
"TempFileLocation"=dword:00000001
"PacketLength"=dword:00000020
"ThroughputThreshold"=dword:00000028
"DeviceSetting"=dword:00000000
"InitMinStorage"=dword:00000008
"PurgeMinStorage"=dword:00001400
"MaxTransferDelay"=dword:00000000
"EnableAudioHW"=dword:00000001
"EnableMDP"=dword:00000001
"PlaybackQuality"=dword:00000000
"MemoryRequired"=dword:00000008
"RemoveFeedFiles"=dword:00000001
"ProgramGuideStyle"=dword:00000000
"PDPWarnning"=dword:00000000
"MaxBufferSize"=dword:00001388
"MaxHistory"=dword:00000032
"DumpMsg"=dword:00000000
"DumpKernelMsg"=dword:00000000
"SDKLogFlag"=dword:00000000
"PlaybackLog"=dword:00000000
"DisplayBuffer"=dword:00000001
"DisplayThroughput"=dword:00000000

[HKEY_LOCAL_MACHINE\SOFTWARE\HTC\ConcurrenceMgr\Timeout]
"HTCYouTubeClient_WorkWnd"=dword:000003E8

[HKEY_LOCAL_MACHINE\SOFTWARE\HTC\ConcurrenceMgr\Wnd]
"HTCYouTubeClient_WorkWnd"=dword:00000002

[HKEY_CLASSES_ROOT\Filter\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}]
@="Vo PD Source Filter"

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}]
@="Vo PD Source Filter"
"Merit"=dword:00400000

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}\InprocServer32]
@="voFltPD.dll"
"ThreadingModel"="Both"

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}\Pins]

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}\Pins\Output]
"AllowedMany"=dword:00000001
"AllowedZero"=dword:00000000
"IsRendered"=dword:00000000
"Direction"=dword:00000001

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}\Pins\Output\Types]

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}\Pins\Output\Types\{73646976-0000-0010-8000-00AA00389B71}]

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}\Pins\Output\Types\{73646976-0000-0010-8000-00AA00389B71}\{20F4471A-BB3C-4d5b-A8AE-D1112E754784}]

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}\Pins\Output\Types\{73646976-0000-0010-8000-00AA00389B71}\{974AB41B-9C59-48da-8497-70AA926D09BA}]

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}\Pins\Output\Types\{73646976-0000-0010-8000-00AA00389B71}\{AB667918-5722-458f-AD3D-395A2DAB5879}]

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}\Pins\Output\Types\{73646976-0000-0010-8000-00AA00389B71}\{DE6B7991-E5B0-4951-A582-0F7466D2E54D}]

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}\Pins\Output\Types\{73647561-0000-0010-8000-00AA00389B71}]

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}\Pins\Output\Types\{73647561-0000-0010-8000-00AA00389B71}\{D3E73EDD-DEB1-41be-912B-C76FAFBA11CF}]

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}\Pins\Output\Types\{73647561-0000-0010-8000-00AA00389B71}\{14039CD0-16D3-496e-A040-3AC3E11FF355}]

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}\Pins\Output\Types\{73647561-0000-0010-8000-00AA00389B71}\{70394030-AC5C-417b-AD9A-998AAA65B97C}]

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}\Pins\Output\Types\{73647561-0000-0010-8000-00AA00389B71}\{25CC8C8F-F93B-4480-968D-B646B8BE295C}]

[HKEY_CLASSES_ROOT\CLSID\{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}\Pins\Output\Types\{73647561-0000-0010-8000-00AA00389B71}\{6541ACF5-C2FE-4A34-8314-B2E7A526ACDC}]

[HKEY_CLASSES_ROOT\CLSID\{0BC3DE55-F3B9-453d-81F8-621D717824D5}\Pins\Video In\Types]

[HKEY_CLASSES_ROOT\CLSID\{0BC3DE55-F3B9-453d-81F8-621D717824D5}\Pins\Video In\Types\{73646976-0000-0010-8000-00AA00389B71}]

[HKEY_CLASSES_ROOT\CLSID\{0BC3DE55-F3B9-453d-81F8-621D717824D5}\Pins\Video In\Types\{73646976-0000-0010-8000-00AA00389B71}\{9D4E3333-807A-4d85-96C3-C8585E037873}]

[HKEY_CLASSES_ROOT\CLSID\{0BC3DE55-F3B9-453d-81F8-621D717824D5}\Pins\Video In\Types\{73646976-0000-0010-8000-00AA00389B71}\{61107F35-FBCE-4709-9F0D-B5BEFCE61DE2}]

[HKEY_CLASSES_ROOT\CLSID\{0BC3DE55-F3B9-453d-81F8-621D717824D5}\Pins\Video In\Types\{73646976-0000-0010-8000-00AA00389B71}\{19D5C074-FE05-4c8c-B699-4E15665D3046}]

[HKEY_CLASSES_ROOT\CLSID\{0BC3DE55-F3B9-453d-81F8-621D717824D5}\Pins\Video In\Types\{73646976-0000-0010-8000-00AA00389B71}\{47504A4D-0000-0010-8000-00AA00389B71}]

[HKEY_CLASSES_ROOT\CLSID\{0BC3DE55-F3B9-453d-81F8-621D717824D5}\Pins\Video In\Types\{73646976-0000-0010-8000-00AA00389B71}\{0B55D6D1-F6C2-4f3c-8927-E0082F0C3BF9}]

[HKEY_CLASSES_ROOT\CLSID\{0BC3DE55-F3B9-453d-81F8-621D717824D5}\Pins\Video In\Types\{73646976-0000-0010-8000-00AA00389B71}\{20F4471A-BB3C-4d5b-A8AE-D1112E754784}]

[HKEY_CLASSES_ROOT\CLSID\{0BC3DE55-F3B9-453d-81F8-621D717824D5}\Pins\Video In\Types\{73646976-0000-0010-8000-00AA00389B71}\{974AB41B-9C59-48da-8497-70AA926D09BA}]

[HKEY_CLASSES_ROOT\CLSID\{0BC3DE55-F3B9-453d-81F8-621D717824D5}\Pins\Video In\Types\{73646976-0000-0010-8000-00AA00389B71}\{AB667918-5722-458f-AD3D-395A2DAB5879}]

[HKEY_CLASSES_ROOT\CLSID\{0BC3DE55-F3B9-453d-81F8-621D717824D5}\Pins\Video In\Types\{73646976-0000-0010-8000-00AA00389B71}\{DE6B7991-E5B0-4951-A582-0F7466D2E54D}]

[HKEY_CLASSES_ROOT\CLSID\{30F82E17-17B4-4ad7-9887-2F9C249B1C2F}\Pins\Audio In\Types]

[HKEY_CLASSES_ROOT\CLSID\{30F82E17-17B4-4ad7-9887-2F9C249B1C2F}\Pins\Audio In\Types\{73647561-0000-0010-8000-00AA00389B71}]

[HKEY_CLASSES_ROOT\CLSID\{30F82E17-17B4-4ad7-9887-2F9C249B1C2F}\Pins\Audio In\Types\{73647561-0000-0010-8000-00AA00389B71}\{F7C3456F-1C81-43c1-85B3-34D430886901}]

[HKEY_CLASSES_ROOT\CLSID\{30F82E17-17B4-4ad7-9887-2F9C249B1C2F}\Pins\Audio In\Types\{73647561-0000-0010-8000-00AA00389B71}\{366F7D20-54F6-4190-A68C-0CF289AC6407}]

[HKEY_CLASSES_ROOT\CLSID\{30F82E17-17B4-4ad7-9887-2F9C249B1C2F}\Pins\Audio In\Types\{73647561-0000-0010-8000-00AA00389B71}\{D3E73EDD-DEB1-41be-912B-C76FAFBA11CF}]

[HKEY_CLASSES_ROOT\CLSID\{30F82E17-17B4-4ad7-9887-2F9C249B1C2F}\Pins\Audio In\Types\{73647561-0000-0010-8000-00AA00389B71}\{14039CD0-16D3-496e-A040-3AC3E11FF355}]

[HKEY_CLASSES_ROOT\CLSID\{30F82E17-17B4-4ad7-9887-2F9C249B1C2F}\Pins\Audio In\Types\{73647561-0000-0010-8000-00AA00389B71}\{70394030-AC5C-417b-AD9A-998AAA65B97C}]

[HKEY_CLASSES_ROOT\CLSID\{30F82E17-17B4-4ad7-9887-2F9C249B1C2F}\Pins\Audio In\Types\{73647561-0000-0010-8000-00AA00389B71}\{25CC8C8F-F93B-4480-968D-B646B8BE295C}]

[HKEY_CLASSES_ROOT\CLSID\{30F82E17-17B4-4ad7-9887-2F9C249B1C2F}\Pins\Audio In\Types\{73647561-0000-0010-8000-00AA00389B71}\{6541ACF5-C2FE-4A34-8314-B2E7A526ACDC}]

[HKEY_CLASSES_ROOT\http\Extensions]
".mp4"="{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}"
".3gp"="{C85643AD-97B6-486c-9BC0-C61B4DF6C58E}"

[HKEY_LOCAL_MACHINE\SOFTWARE\OEM\MASD]
"YouTube"="1_0_1815_3318"

good luck ;)