so i have an ATI card...very old, and i wanna switch to nvidia geforce 550 ti , but when i put it in, and turn on i get blank screen. so i put old card in so i can intall the driver for gefore but it wont let me because its not plugged in... help?

Are you sure the blank screen is because of a driver issue?

When is the screen blank? The whole time? After the BIOS screen? etc...

A likely cause is that your PSU isn't powerful enough to supply steady power to your fancy new GPU.

i acttualy just hooked up a new 600 watt PSU to run this new GPU, and yes i turn on and its blank the whole time....

Does your motherboard have a built graphics? Cause I'm wondering if you can uninstall the old drives of your ATI card through that, then hook up the new Nvidia and install it? But then again if it wont even boot through Bios I'm wondering if it's a card malfunction.

If my memory is correct all cards should have some sort of default display that can load without it's drivers on the machine, but if nothings happening, it could be a malfunction. Is your card used or brand new with all it's anti-static shielding?

Another thing that I think it could be the reason is the motherboard not being able to support it for some reason, like it wont support PCI express 2.0 or something, but it kinda doesn't sound likely.

it was brand new...but iv been reading and idk if my system can use it, or i might need to update some things... how do i find this info out?

I would try to make sure my BIO system is up to date and look and see if anyone could be having the same issues with the motherboard your using. I'm sure there is at least people out there whom had the same issue.

Making sure if the drives/bios are to date is a bit tricky with some companies such as Dell or HP sometimes... They can be jerks about it. =/ But if it's a home made system I would try looking up the makers of the motherboard.

i think i need to update my compter specs anyway, it was custom built about 1 and half years ago and i havnt really kept it up. what are all things i need to update to keep my computer up to date, w\o getting more hardware? im pretty sure the motherboard is pretty good. got 600w PSU and, 3.0 gz intell cpu... 3g or ram. ...just can someone give me a site thats not a scam that legit helps me with keeping my comp updated?

how do i find out my motherbaard and bios info?

There are two great utilities that give all sorts of info on mobo and graphics hardware...

CPU-Z can identify the types and specs of your processor, motherboard, RAM, and some basics on your graphics hardware
GPU-Z can give you details on your graphics card(s).

Additionally, I'm rather a fan of speedfan, which can tell you what the internal thermometers are seeing, how fast fans are going, and retrieve hard disk health info.

What was your old ATI card? If it's very old it may have been using a PCI bus whereas your GTX 550 Ti uses a PCI-E bus which will obviously prevent it from communicating with the motherboard at all (but then you shouldn't have been able to plug it into the motherboard at all IIRC). Is the DVI/whatever you're using cable properly plugged in the monitor and in the graphics card?

Is the motherboard/graphics card making any noise (like beeps)? Is the motherboard's beeper on (some people don't bother to plug it on but it's useful for debugging issues since the number of beeps will tell you what's wrong). Most medium/high-end graphics cards (like yours) require a secondary power connection, did you plug it in? You may have missed it.

ajm113 is right, all cards will provide basic VGA function. If you are getting no output at all then you have forgotten to plug something (most likely) in or there something seriously wrong.