Old computer upgrade

[Worstcaster]

My father has a HP Pavilion 500-336 desktop which is running slow.  I'm thinking of upgrading him to a 500 GB SSD for Christmas.  The PC has a 1 TB HDD but he is only using 74.3 GB of that drive.  I can't crack the case open without telling him what I am planning.  Has anyone done a similar upgrade with this machine?  I searched the MOBO and it does have SATA connectors.  I can't find pictures of the power supply used.  I'm just wondering if it has more than one SATA power connector, so I can clone the HDD to the SSD in machine.  My father uses some old programs for generating CPR cards.  I tried to get that program to work on my laptop and couldn't.  I'm worried that if I do a fresh Windows install it could break that program.  It is called Omni form and apparently it is not sold anymore, so no new or updated software for it.  I'm posting links to the MOBO and what I could find of the power supply.  I heard a program called Macrium Reflect could clone the HDD to the smaller SSD.  Has anyone used this software?

 

https://support.hp.com/us-en/document/c04345595

 

https://support.hp.com/us-en/document/c03885123

[aisle9]

"Old" my ass, that's a Haswell system. You're golden. Install the SSD with the HDD still in there, then use Macrium Reflect to copy/clone the drive over and resize the partitions (it'll tell you what to do). You're golden. Hell, that's the sort of computer I'd try to get my hands on, because if you drop a cheap Xeon E3-1231V3 processor and an RX 570 in there, you've got a gaming rig.

[Worstcaster]

Great thanks.