Hi

Few days back i built Qwt foe visual studio 2010,, Here is what i have done

1. Instead of Building QT from the source, download Pre Built libraries available for Vs 2010 from the Qt website. Add the Qt bin folder path to the Path variable
2. Download the Latest Qwt i.e 6.0.1
3. Open the Visual Studio 2010 command prompt, not the normal Command prompt
4. do as suggested in the install file of the Qwt folder..i.e qmake Qwt.pro,nmake,nmake install...
5 .These are the steps i followed and was able to build the Qwt project successfully.