I gave a friend of mine my GeForce 9400 to replace his crappy integrated GeForce 6150 graphics. (don't tell me to get a better graphics card, he plays games like LoL and Dota, and it works perfectly for that) After installation, we noticed that the computer was loading painfully slow. If we switch back to onboard graphics, it becomes as fast as it used to be. When Windows asks me if I want to boot in safe mode or in normal mode, when I press enter, you see the message slowly wipe to the bottom. Safe mode is also painfully slow at all times. We tested the hard drive performance with a tool, and we saw performance spikes at a very regular interval of maybe 4 seconds. Loading anything takes an eternity, but in-game performance proved to be way better than the integrated gfx, nonetheless.

I don't know how installing a new graphics card would alter loading speed or why it would cause the safe mode selection screen to slowly wipe away.

The computer is an eMachines EL1321, we upgraded the PSU to accommodate the card's wattage requirements, and moved it to a bigger case to allow the GPU to fit inside. We removed and re-installed the drivers when we put in the new card.

I'm out of ideas, what NEXT?What CPU and how MUCH RAM is in this system? Adding a Geforce 9400 video card, the video card is probably sharing some of its memory with that of the system. I have seen Video Cards that grab some system memory as its own as shared such as a GeForce 8400 GS that I have that is a 512MB Card that grabs 256MB system memory in systems that its installed into. If this system was already running on bare minimum memory  the video card can steal a portion of this system memory and hurt performance causing more data to have to page in the swap file of the hard drive.The CPU is an AMD Athlon 2 X2 and it has 3 GB of RAM. The card is supposed to have 1 GB of GDDR2, it says it on boot and on the sticker on the back of it. I have tried the card in my own (Linux) computer and it was loading as fast as with my 8600 GT. Should we try disabling swap?What is the exact make/model of the video card? Going to check into its specs to see if it grabs a system memory allocation. Disabling swap space would probably make it worse as for I believe your DEALING with a low memory situation.

With the card out I would look to see what it shows for FREE memory and then with the card installed look at the free memory count?