I finally got around to installing Oracle 11g on Windows 7 Professional Edition, 64-bit. The only catch was that the Oracle 11g (11.1.0.7) installer validates only against Windows 5.0, 5.1, 5.2 or 6.0. Windows 7 is actually Windows Code Base 6.1, as seen in this screen shot after successful installation:
Windows 7 上市廣告..可愛的小女孩
Brief Description Install this update to resolve issues with non-compatible applications for Windows 7 Beta.
— Download details: Update for Windows 7 Client Beta (KB967062)