If you want to IE10 web browser control to show page without doctype, you need to set both of the following registry keys to make it work.
Key: HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION
Value: yourappname.exe
Type: (DWORD_32Bit value)
Data: 0x2711
Key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\MAIN\FeatureControl\FEATURE_USE_QME_FOR_TOPLEVEL_DOCS
Value: yourappname.exe
Type: REG_DWORD (DWORD_32Bit value)
Data: 1