If you have no data on the HDD to save have a look at Step One in this tutorial at the link below to do a wipe (secure erase) and then create a single partition to install Windows 7 to using the outline in Step Two #2.
its the first time i failed in troubleshooting something regarding Windows .... am going to install XP and see if the problem persists ... any Help regarding installing Windows XP via Sandisk 16GB would be appreciated