Windows 7 - Computer won't boot up after installing graphic card

HI I bought a evga 550ti card and put it in my computer but when I turn it on it gets to the starting windows screen and then shuts off. Any help would be nice

But your computer worked fine before?
Reboot your computer, tap F8 once a second or so from power on. Select "safe mode" does that work?
Advanced Boot Options
Also select
Prevents Windows 7 from automatically restarting if an error causes Windows 7 to fail. Choose this option only if Windows 7 is stuck in a loop where Windows 7 fails, attempts to restart, and fails again repeatedly.

so you can see the crashscreen instead of restart

Have you installed the driver yet ?

First try run Startup Repair , at least three separate times with restarts after each single run, after marking either the system reserved hidden partition or the C drive as active using the tutorial Partition - Mark as Active .

Startup Repair - Run 3 Separate Times

If still fails, boot into Advanced Boot Options , and try the Last known good configuration (advanced).

Let us know what happened .

reboot in "safe mode" and uninstall all stuff related to old graphics card. uninstall the graphics card device driver as well using "device management". Reboot again and try normal mode otherwise safe mode again. Now insert your driver CD that you get with graphics card. Or let windows detect it and install its drivers

geforce nvidia driver isn't it? Drivers - GeForce
push the "Auto detect your GPU" button there and follow instructions

ok so I installed the card and the drivers but the only way I can start the computer is in safe mode, normal mode still crashes when the starting windows screen appears. I ran the card installation from the cd and from the geforce auto detect link above and both installed fine

Please post crash information. Disabel auto restart on crash!
To disable automatic restart, press WINDOWS KEY + PAUSE/BREAK to load the System Properties Dialog (you can also access this via the Control Panel > System). Then click on "Advanced Settings":



Then, select Settings in the "Startup and Recovery" area:



This will load the Startup and Recovery window, allowing you to untick the Automatically Restart box and then click OK:

Did you unistall all leftovers from old card?

Just before upgrading the GPU you didn't have any problems? So it must be the GPU? please confirm

Also consider the possibilty of other programs causing conflict, where it didn't before.
Use msconfig to disable all the programs loaded at startup. then reboot and put the tick back in the box for each one, reboot after each one. If there is a conflict you will find out when you have just added it back, if that happens, disable that one again and continue until you finish the list.
Don't worry for now what you disable, if a program really needs something running, either that program\function just plain wont work, or you'll get an error message.
There are ways to get things to work together, but just try to fix the booting problem first.