OK, first things first. Hi, I have a spare PC I use for coding at home with similar specs.
It has a HD5450 (Reference card from ATI).
Core 2 Duo E7500 2.93Ghz
Gigabyte GA-31MX board
4gb ram
300W PSU
Windows 7 Pro 32 bit.
My Question is :
Did you have a PCi-X card installed ?
If yes, was it an nVidia / ATI card / other / onboard gfx?
The geforce could have worked because you had a old nVidia card in, and simply swopped it out for another/new nvidia card,and the driver is compatible with the 'new' card as it is already installed, explaining why the 210 did work.
It won't work if some other manufacture's drivers was loaded and you simply took the old card out and inserted the new ATI card and booted up the pc and windows couldn't properly remove the previous driver.
A better way to install a new gfx card:
You need to Uninstall the gfx driver
with 'Computer Management' -> 'Device Manager' / gfx uninstaller utility(if it is available) before shuttting down and removing the old card.
This is so that Windows can revert to a standard driver before forcibly loading the old driver into memory during boot(Yes,this happens during the windows logo animation when windows starts, and when your 'Stops' occurred).
So next time when it 'Stops', reset, Press and hold the control-key(not during the BIOS post screens, you might get a KB error) right before windows loads to get a startup mode selection, choose safe mode and uninstall all gfx software and drivers as mentioned, then reboot and load windows as normal.If windows boots successfully,go grab your driver cd that came with the card and install the software.
(If that doesnt work, insert the windows install disc and do a repair.)
When your done go back to the shop you bought it from and through a banana at the 'man' who tried to install it, as he clearly doesnt know what he is doing...^^
And b.t.w, I think the HD5450 is better in every aspect than the geforce 210, at least a 240 will almost compare.
A 210 is VERY lightweight...