hi
i have downloaded the qt open source version from trolltech for windows, and in have installed this in win xp sp3.Now what r the things to be done before running a project in qt creator ,if i run qt creator it says error like

No valid Qt version set. Set one in Tools/Options
Error while building project windowspositioning
When executing build step 'QMake'
Canceled build.

im trying this also ,and i could not find any proper steps to confiure the qt in win xp
and some one says there are some environment variables to be set..i don know wht to do can any one help me because i need to do complete application in qt.so i need to know the details. and im using qt-sdk-win-opensource-2009.01.1.exe
pls help me ......