need a good gpu for my mom's computer

as per title i need a good gpu for my moms computer.
here are the specs
mobo: intel d945gcl
ram: 4gb 667mhz
psu: antec vp450f
CPU: core2duo E6700 2.66ghz
OS: windows 10
BUDGET :$100-$150
she just uses the pc for internet browsing and youtube videos and plays a little bit of games but not much.
right now i have a a cheap hd3470 that i bought dirt cheap brand new on her pc but it wont run windows 10.
i just want to get her something that will last and doesnt bottleneck with the cpu a whole lot just trying to get the most out of her pc.
THANKS IN ADVANCE
RUBEN

Ruben, please only create one thread per topic. I removed the other two.

What case/chassis, so as to know what length of card will fit.

least expensive card I can find is: http://www.newegg.com/Product/Product.aspx?Item=N82E16814127800&ignorebbr=1

It is PCI-e 3.0, whereas the board is 1.0...being that the specifications are backwards compatible, it should reduce speed to the lower capability.

Only problems I can think of are: Will that board work with this card, and will the PSU deliver the current necessary.
The listed power requirements are: Power consumption: 64W / Recommended Power Supply: 400W.
I have no knowledge of the specs of that Antec.

Wait for some others to reply, as they may have some better ideas.

for her needs a little 6450 would do just fine.