# Black screen after Windows 7 install on late 2009 iMac

Boot into MacOS, install either [<span class="caps">NTFS</span> Mounter](http://ntfsmounter.com/) or [<span class="caps">NTFS</span> 3G](http://macntfs-3g.blogspot.com/) in order to make the <span class="caps">NTFS</span> partition writable.

On the Windows OS drive, delete the existing <span class="caps">ATI</span> driver:  
`/Windows/System32/Drivers/atikmdag.sys`

Reboot into Windows 7, download the latest <span class="caps">ATI</span> HD 4850 driver from <span class="caps">AMD</span>.

Note: Apple’s [alleged fix](http://support.apple.com/kb/TS3173) for this graphics card driver issue is a dud.