Computer won't boot after video card change

[kevmachine]

Hey all, a buddy of mine bought a new video card and I was gonna try it out in my system to see what it was like, but the thing is, after installing it, It's a gtx 260 btw, into my pc, the computer won't post, it's just a black screen with no signal message, and the weird thing is, the fan on the gtx 260 goes to like 100% then down then back up over and over. the card works because it works in my friends system, i even tried his psu in my tower and still nothing, my video card, a hd radeon 5450 works fine in my computer. I am at a loss as too what the promblem would be. could it be my motherboard is too old perhaps? something im doing wrong? someone said to remove all my graphic's drivers first, but I thought that it wouldn't matter since the drivers automatically are suppose to update and since my computer won't even boot what's the point. Should I try this? maybe even download the drivers for the gtx 260 before i even put it in? I have all the connections right the 6 pin's and all that.

Any help would be much appretiated.
Thank you.

 

[kevmachine]

Hey all, a buddy of mine bought a new video card and I was gonna try it out in my system to see what it was like, but the thing is, after installing it, It's a gtx 260 btw, into my pc, the computer won't post, it's just a black screen with no signal message, and the weird thing is, the fan on the gtx 260 goes to like 100% then down then back up over and over. the card works because it works in my friends system, i even tried his psu in my tower and still nothing, my video card, a hd radeon 5450 works fine in my computer. I am at a loss as too what the promblem would be. could it be my motherboard is too old perhaps? something im doing wrong? someone said to remove all my graphic's drivers first, but I thought that it wouldn't matter since the drivers automatically are suppose to update and since my computer won't even boot what's the point. Should I try this? maybe even download the drivers for the gtx 260 before i even put it in?

Any help would be much appretiated.
Thank you.

also he had his old video card a gt 220 and that worked in my system just not the gtx 260.