I would start out by stating my rig (it's old don't judge me)
CPU: Intel Core 2 Duo E7500 clocked in at 3.2 GHz
GPU: Sapphire Radeon HD 7870
RAM: 6GB DDR3
Case: Antec 300
Anyways, my Radeon HD 7870 is fairly new, I got it as a gift. When I came to install it, I discovered that it won't fit in because the motherboard's layout means it will collide slightly with the CPU's unusually big fan. What is the best option here? Do I purchase a new motherboard? Or do I get a new CPU cooler? Also suggestions would be nice as to how I could make the system better.
Do you have a picture of your system so I can see what we are talking about? Sometimes CPU coolers can go different directions, so maybe you could rotate it 90 degrees. But I don't know exactly what yours looks like.
I would say it's probably time for a new MB/CPU/RAM so that could be an option if you have $200-300 to spend. I would not buy another Core 2 MB.