As of December 31st, 2009 Capture One 3.7.8 and below will cease to run on all windows machines.
The issue is clearly just a small fault in the Software' code and can easily be remedied by updating to Capture One 3.7.9.
http://xchange.phaseone.com/home/Conten ... nguageid=1
The Link above is for Capture One PRO 3.7.9 and DB.
If you have been using Capture One LE please update to Capture One 4.