I'm having this problem also. I support a number of apps that use the Oracle OLE DB provider and now the provider isn't working in Windows7 with Oracle 11g. The machines that had Windows XP at first got the same runitme 3706 "Provider not found" error that the Windows 7 users are getting, but I registered the provider using regsvr32 OraOLEDB11.dll. I'm still getting the error with the Win7 users, however. I downloaded ODAC on my home Win7 machine and confirmed that even after registering with both version of regsvr32 (and a reboot), the OLE DB provider doesn't show in an a .udl file like all of the other installed OLE DB providers. I got the "regsvr32 succeeded" message at the end, but nothing in .udl.
Will someone from Oracle please look into and comment on this!? This is a big problem!