Hi,
while using Ubuntu, i don't care about win7 ;) but found also a way to solve that "import qgis.core"-problem and close this thread.
Its for Win7 x64 professional:
Install first QGIS (1.7 with OSGeo4w to C:\OSGeo4W) then QT (if needed) and at last Python 2.5 to C:\OSGeo4W\apps\python25
Add some paths to environment Variables: to PATH: C:\OSGeo4W\bin; C:\OSGeo4W\apps\qgis\bin\ to PYTHONPATH: C:\OSGeo4W\apps\python25
If you want to use eclipse don't forget to set the Preferences on Pydev.
---
jens s.