The Intex IT-305WC webcam is not listed in the Windows 7 compatibility. The webcam is only compatible with Windows XP and Vista on the manufacturer's website, so you may install the webcam drivers in compatibility mode.
Right click the installation file and select Properties.
Click the Compatibility tab.
Under Compatibility mode, check the Run this program in compatibility mode for: option.
Select Windows Vista sp2
Click Apply and OK.
Run driver as administrator.