There was no option to disable the front panel jack detection. Unfortunately my version of the Realtek driver didn’t look like the one in the screenshot above, so I needed to try something else. I found a solution in Tom’s Hardware Forum (click on the photo to enlarge it): Everything worked fine, except that I got no result, the Realtek audio manager didn’t seem to detect my headphones. I downloaded the latest Realtek High Definition Audio Codecs from here then installed the package. The first thing to try was to check if Realtek has any Windows 7 drivers. That was a bit annoying, because I wanted to have the speakers plugged in the rear jack and the headphones in the front jack, so I can use whatever I wish without needing to plug and unplug cables all the time. However, there was a minor glitch: the front panel audio jack stopped working.
The new operating system just recognized everything (less the printer, but that’s another story). When I switched from Windows XP to Windows 7, I was happy I didn’t need to install any drivers.