Last week I bought the Sapphire HD5850 from my brother. I was still using a Sapphire HD4850, so I thought it was a good upgrade.

So I followed the normal instructions of how to install the graphics card. Everything went fine until the reboot after the installation of catalyst 13.1.

After the boot of windows 7, when the logo has gone and normally the login screen shows up, my PC blue screens, shows a black screen or the screen is showing half the login screen (which is frozen).
At the BSOD it says atikmpag.sys is involved in the crash, so... 

I have tried everything I could like using older drivers, tweaking the power supply to the graphics card and so on, but without a solution.

But when I put my HD4850 back in it, it will just work fine again...

My specs:

OS: Windows 7 64-bit service pack 1
Motherboard: MSI P-45 NEO
CPU: Intel Core 2 Quad Q6600 @ 2.4Ghz
Powersupply: Cooler Master Real Power M520
Additional Hardware: 1 HDD, 1 SSD, 1DVD RW drive, 3 case fans and a network card

 I hope I gave enough information so someone can help me with this.

Yes...you must first uninstall all the software for the 4850 before trying to install the drivers for the new card. You must also have the latest .netframework installed. How to do a clean install and how to get the latest .netframework both have tutorials in the FAQ section of this forum.

Intel I7 960 @ 3.87ghz *Intel DX58SO *HIS HD6970 2gb *Corsair TX650M *2x4gb Corsair XMS3 *WD Black 1TB *Windows 7 Home Premium 64bit *Gateway HD2401 24" 2ms 1920x1200  ***Asus N71Jq laptop *Intel I7 720QM Processor *Mobility Radeon HD5730 1gb *8gb Ram *Windows 7 64bit  ***Acer 5750 laptop

* A clear conscience is usually a sign of bad memory *

Well, I followed the guide to install the driver (.netframework 4.5 is installed) but at the point where you have to install the new driver something weird happens:

The install manager only shows 3 components to install, which are AMD catalyst install manager, AMD APP SDK runtime and HDMI/DP audio driver.

So CCC isn't in the list, which is kinda strange.

Go to safe mode and use Driver Fusion or Driver Sweeper to get rid of all AMD related drivers, boot OS normally and install drivers for the HD5850. ~clean install

Ok, it installed CCC correctly.

But it still doesn't work, still freezes at the reboot after the installation of CCC.

Any other suggestions?