Impossible to find HP Accessory Center on HP websites

[Ralph-T-in-NYC]

Why won't my 965 Wireless Ergonomic Keyboard and 925 Wireless Ergonomic Mouse work?  Where is HP Accessory Center?  How can I download it?

I am furious at HP.  I have a long series of complaints but I'm going to focus on one of several immediate problems.  

HP shipped the 965 Wireless Ergonomic Keyboard and 925 Wireless Ergonomic Mouse the day I placed my order.  They finally shipped the 25L PC I had ordered a month later.  It proved defective within a few weeks.  They took a month to ship what I needed to return it; and quickly shipped the replacement when I told them I would be away for two weeks.  Now the replacement 16L does not work with the Keyboard and Mouse.  The defective 25L did work with the keyboard and mouse easily SOMETIMES (it would occasionally 'lose them" along with at other times not finding any software on the disk).  I did come across the HP Accessory Center software early in my attempts to make the system stable.  Now I simply cannot use the keyboard and mouse with the 16L and I hope the HP Accessory Center will help me activate them.  This support tool / site won't allow me to select the 16L even though it said it had added the PC to my profile.  

[Ralph-T-in-NYC]

Well, I found the HP Accessory Center in / on the Microsoft Store, BUT it does not tell how to fix the problem.  Reset is an option for the unifying dongles, BUT there is no guidance about whether to use only and whether resetting will fix the problem.

WHY DOESN'T THE HP SITE DIRECT ME TO THE MICROSOFT STORE FOR THE HP ACCESSORY CENTER?  I had a screen shot I took from it on the defective PC, so search via Windows discovered that but did not direct me to the Microsoft Store.

WHY IS THERE NO GUIDANCE FOR THESE TWO DEVICES?????