Does oracle client 12c requires Java on windows

I found the problem. For reasons I don't understand Oracle needs access to the file system through the administrative network share (i.e. \computer\c$) and I had disabled it.

Things to check to solve this issue:

1. Remove your computer from workgroups.
2. Set HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System DWORD value LocalAccountTokenFilterPolicy to 1
3. Set HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\LanmanServer\Parameters DWORD value AutoShareWks to 1

The install/oraparam.ini contains the following lines (even in a fresh download):

#MSVCREDIST_LOC flag will provide the name of the exe that is being shipped in stage/ext/bin  
MSVCREDIST_LOC=vcredist_x64.exe

This is incorrect because you need the 32-bit version (x86).

Now if you check stage/ext/bin, there is a file vcredist_x86.exe, and obviously no x64, since it is a 32-bit installer. Try editing oraparam.init and fixing the above line to:

MSVCREDIST_LOC=vcredist_x86.exe

Another possibility is that you need to install the Microsoft C++ 2010 Redistributable manually: http://www.microsoft.com/en-us/download/confirmation.aspx?id=5555