I am having trouble figuring out if I can install a PCI-E x16 usb 3.0 express card into my HP pavilion a6430f.

Shouldn’t be a problem. Both are PCI Express.

Hi @anonymous6059, welcome to Fluther!

1)
The card goes into a PCI Express x1 slot (rather than x16).

See pictures here of the difference slot size, and compare to the photo in your Amazon link.

2)
According to the specifications I see online at HP, your computer has two PCI Express x1 slots.

So you need to check that you have one open PCI-E x1 slot.

There is still a question. Does the computer have a free 4-PIN or SATA power connector?

There’s a 4-pin socket on the card. And the card includes an adapter for a SATA power connector (see the photo with “SATA to 4-PIN male adapter”).

Yes, my computer does have two PCI express x1 slots. I don’t know why I thought I had to use the x16 slot. The computer has for the most part never been modified before. Where would the additional SATA connectors be at inside the PC?

So, basically it will work as long as I can find a free SATA power connector? I mean that we agree that the PC will accept the card that I have looked at on amazon, right? I just now need to find where to plug it in…

What about using this one instead? Somehow it doesn’t need additional power source?
http://www.amazon.com/Cord-free-Expansion-Controller-Additional-Connection/dp/B00JFR2I2C/ref=sr_1_2?s=electronics&ie=UTF8&qid=1422914463&sr=1-2&keywords=USB+3.0+PCI-E+Express+Card

I think my PC has “Molex” connections does that mean anything?
or maybe not…

A Molex connector is the 4-PIN connector, so that is good news.

The SATA and Molex power would be hanging off the power supply like this

I am not sure how the two cards compare, whether the power connector makes it better.

Hopefully someone else here can comment on that.

Jaytkay you have given me a great deal of advice, thank you!

I think I will try this one because it seems to have everything add even some extra wires just in case I am wrong about which type my PC seems to have. http://www.amazon.com/Inateck-Superspeed-Ports-PCI-E-Expansion/dp/B00B6ZCNGM/ref=sr_1_1?s=electronics&ie=UTF8&qid=1422914463&sr=1-1&keywords=USB+3.0+PCI-E+Express+Card