Windows 7: Windows 7 MIDI input problem

I tried to attach a M-audio 88es USB MIDI keyboard to my Dell Studio 1747 laptop (Windows 7 Home Premium x64). The keyboard is correctly identified on the USB, M-audio's drivers installed and this shows up in any MIDI software I start, but nothing can be transmitted from the keyboard to the computer.
The usb keyboard works with other computers, and the Dell Studio sound system can play MIDI files. To make sure I alternated to an external Creative XFi soundblaster audio unit, which should have all MIDI capabilities, but again no sound from the keyboard (actually, a field in the recording software would show up if MIDI instructions were received).
Is there more I can try?
novator

I have a home recording studio using Sonar X1.

Have you tried uninstalling the keyboard, restart the PC and then do a new install? If not, give that a try.

Connect the Keyboard, then go to the Device Manager. Right click to Higlight the entry for the Keyboard and then Left click "Uninstall". Disconnect the keyboard from the PC. Restart the PC and after Windows starts connect it and if you did not also uninstall the drivers Windows should detect it and reinstall it. If there were some type of corruption in Windows this will fix that.

Thanks Fireberd,
I tried the uninstall/reinstall trick, and all went smoothly, except that the no sound problem did not go away.
Regarding the 3 usb connectors on the Dell Studio, they all work with external harddisks and mobile phone transfers, but I had a strange experience with a Pinnacle/Hauppauge PCTV usb nanostick. It also seemed to install correctly, but could not receive signals to the vendors TV recording program. However, I then went into Microsoft Media Center and it readily started the TV station search that the dedicated software could not. That solved the TV problem, provided that I can live with recording only in the .WTV format.
Could there be some general screening out of "non-certified" third party programs by one of the Microsoft installs? As Microsofts media programs offer no MIDI keyboard input I cannot test this for the MIDI problem, or can I?

Try installing something that has midi input, such as Anvil Studio Catalog

I tried several MIDI input programs, including Ableton Lite (that came with the USB M-audio keyboard), Mixcraft5 and also Anvil Studio. How else could I tell that MIDI signals were not received?

Have you tried the AVID forums? Avid owns MAudio and here is the link to the MIDI keyboard section of their forum:
MIDI & Keyboards - Avid Audio Forums