Drivers are installed when iTunes is installed, but if for some reason there is a need to install the drivers manually they can be download below for most versions of Windows. These drivers switch between 2 USB modes and this will depend on how the phone or tablet was booted. The modes are:
iPhone:
Regular mode: Apple Mobile Device USB Driver
Recovery Mode: Apple Recovery (iBoot) USB Driver
iPad:
Regular mode: Apple iPod USB Driver
Recovery Mode: Apple Recovery (DFU) USB Driver
(Note: Apple devices give a different HWID for Recovery mode.)
Apple Recovery (DFU) USB Driver Driver
File: Apple_Mobile_Device_Support_Driver_6.0.9999.66_64bit.zip
3a484ad5c316f611dc5a1b2b36669036b757285bfffa405b8bb4f5b826073df8
Apple Recovery (DFU) USB Driver Driver
File: Apple_Mobile_Device_Support_Driver_6.0.9999.66_32bit.zip
49a84b7db02a55629b638607a5b30a0d451d8abc2dcd7da2ed29ba9abba8627c