Jake_131 :
SgtScream :
You can upgrade your graphics card to a gtx 1050 ti while still utilizing your existing power supply. This will be an overall well balanced gpu upgrade for your HP 500-404A and the gtx 1050 ti will be well paired with your i5 4460. The gtx 1050 ti runs on pci-e slot power and requires no additional pci-e connectors from a power supply. The gtx 1050 ti was specifically designed to be installed in low powered systems like your HP 500-404A.
http://www.evga.com/products/product.aspx?pn=04G-P4-6253-KR
Since minimum system power requirements is a 300w power supply, i'd try the gpu upgrade first, before deciding to purchase a new power supply as you might find your existing PSU to be adequate.
Thank you for your response, i think thats the way to go worst case my PC shutsdown due to more power being requested than it can give and no harm done correct? also if i am forced to buy a PSU could i drop it in the future build? or would i need a different size? as the current one appears smaller than usual.
I really think you'll be fine in using your existing power supply. If you look at power supply requirements you'll find manufacturers over exaggerate power needed when deciding the power supply requirements to over compensate for cheaply rated power supplies like the one you have. Just look at how much improvement in NVidia's power efficiency has improved over the past year. If you want to err on the side of caution, you can also get a gtx 1050 ti that's not super clocked, like the link in my post above, as it will likely draw less power:
http://www.evga.com/products/product.aspx?pn=04G-P4-6251-KR
As long as you stay with an ATX form factor power supply, yes you'll be able to use your psu in your next build. You could compare dimensions of your existing power supply to an atx form factor power supply. If there isn't a significant difference in your measurements, chances are it's an atx form factor. If I were you, i'd just go with the gpu upgrade now and purchase whole new system in the future, when you need to.