I've given up on Windows 7 for use with the Korg zero4 mixer on this machine. After yet another fresh re-install and a complete re-calibration/re-tuning the stutter and audio drop outs have gone from bad to worse when it should have got better if not to a very unlikely flawless 100% state of operation. I even went so far as to clean off all the rust like oxidation from the fire wire cable terminals and all the dust and dirt from the fire wire ports. Strangely (or it might have just been my screwed up hearing perception) it seemed to make the sound a lot clearer/crisper although I wasn't actually looking out for that nor had I done it for that purpose to begin with. But after a very brief stint of what was looking like something that was actually working over the newly re-installed and re-calibrated DAW OS it majorly screwed up again. It wasn't even recording at the time either. This was also having installed the DELL power management app with specific power profiles for video edit and DAW use over the generic default flat out high performance settings that come with Windows.  Nothing I do in it fixes it and performance overall has gradually diminished since the time I first used it for such purposes.

Right now I'm just thinking forget windows 7 64-bit for this particular purpose on this machine. Nothing I've tried seems to fix any of the issues. The only one thing I haven't tried yet is Windows XP 64-bit which theoretically should glean better overall system performance based on how the hardware interfacing is handled under XP, the hardware combination dynamic and the actual system drivers. But as ever that’s yet to be seen.  The only problem is getting hold of a clean untainted XP 64 install which seems to be more difficult then getting a hold of rocking horse shit over the past 3 or 4 years, especially the DELL OEM variant with auto activation via the actual BIOS that's installed to DELL machines. 

More antics here if you're interested.