problems with usbExample ASAP

[david_itay]

hey
i'm new with QT.
I've tried to build the project of the usbExample (downloaded fron this site)
but i'm facing few building errors which i'm not sure how to handle.
the project was instructed on my desktop.
I picked for the QT version the "QT 4.8.1.." with all the defaultive conf.
the error i get is
"Failure to read QMAKESPEC conf file c:/qt/2010.05/qt/mkspecs/win32-g++\qmake.conf."

after changing the path to the corret directory i get
"command failed with exit code 1120"
"coommand failed with exit code 2"


thank you thank you thank you

Added after 16 minutes:

if sombody knows about the following error it might help !

'g++' is not recognized as an internal or external command

[amleto]

last bit would indicate that g++ is not on your path, but is expected to be.

I think it might be best to start from the beginning and show us the Qt install guide you are working from.

[david_itay]

i will make my point more clear.
after installing Qt Creator IDE and tools
i've opened a project named USBExample by openning
the file USBExample (QT project file)
the first thing I did is building the project but it failed due to the following error :

"
Error while building project USBExample (target: Desktop)
When executing build step 'qmake'
"
so i checked at the Projects Tab and i saw that QT version was : Invalid QT version.
i've changed it to QT 4.8.1 for Desktop - MSVC2010 (Qt SDK) which was my only option and by choosing this option all the fields of qmake , Make (build steps , Clean steps) filled up automatically.

qmake : qmake.exe USBExample.pro -r "CONFIG+=debug_and_release" -spec c:/qt/2010.05/qt/mkspecs/win32-g++
Warning: The tool chain suggested "win32-msvc2010" as mkspec.
Make: jom.exe debug in C:\USBExample
Make: jom.exe clean in C:\USBExample

after building theproject again i got this error :
"
20:49:56: Running build steps for project USBExample...
20:49:57: Starting: "c:\qtsdk\desktop\qt\4.8.1\msvc2010\bin\qmake.exe" C:\USBExample\USBExample.pro -r "CONFIG+=debug_and_release" -spec c:/qt/2010.05/qt/mkspecs/win32-g++
Failure to read QMAKESPEC conf file c:/qt/2010.05/qt/mkspecs/win32-g++\qmake.conf.
Error processing project file: C:/USBExample/USBExample.pro
20:49:57: The process "c:\qtsdk\desktop\qt\4.8.1\msvc2010\bin\qmake.exe" exited with code 3.
Error while building project USBExample (target: Desktop)
When executing build step 'qmake'

"

I HAVE NO IDEA WHAT TO NEXT !

PLEASE HELP.