Windows 7 doesn’t detect nVidia graphics card

PCI-E 2.0 devices are fully backwards compatible, so you should have no problems. The hardware will only function at PCI-E 1.0 speeds, though.

They probably recommend you don't use them in first generation slots for performance reasons, but the GTX550 shouldn't come anywhere near the maximum speeds of 1.x. I have seen both 8800GT's and 9800GTX's working fine in PCI-E 1.0 slots.

I have searched the Web for solutions to the problem of "Event ID 14 from source nvlddmkm", and it seems to be a problem of the Nvidia driver. It also happens for you with the Windows generic driver, because that driver also comes from Nvidia, although normally behind the one found on the Nvidia website.

The only people who reported success were ones who uninstalled all Nvidia software (see the utility Display Driver Uninstaller) and installed an older version of the driver. As they only changed the Nvidia driver, this is definitely a driver problem, born out by the fact that it does not happen on Ubuntu.

Solution 1

Since this used to work, but doesn't any more, probably Windows has updated the driver. As first try, you could roll the driver back :

1. Open Control Panel -> Device Manager, or enter Device Manager in WIN+X
2. Locate the device
3. Right-click and choose Properties
4. Click the Driver tab
5. Click Roll Back Driver
6. Click Yes and then Close
7. Your computer will automatically restart

Solution 2

If this does not work for you, you will have the time-consuming task of finding a driver version that works. Your current driver version is 376.33 from 2016.12.14. Here are some driver versions that were reported as working:

• 353.06 from 2015.5.31, reported as working here, but later retracted here.
• 347.88 from 2015.3.17, reported as working here together with the procedure used

Prevent Windows Update from reinstalling the bad driver

Once you find a driver version that works for you, you will have the problem of preventing Windows from automatically updating it again. See this answer of mine for how to block these updates.