Mouse and key board not working

It's a mini tower sorry, even if I unplug the hdd key board still wont work, I've tried removing the battrey with no luck.

The usb ports have power as will charge a phone but won't reconise anything.

No boot problems it will boot to the log on screen with old hdd with Windows installed, can't enter the bios. When it's booting up before it loads it comes up saying no key board reconised 

The 390 is a relatively old PC.  Which model do you have? Always include that on any initial problem post.  There is a Small Form Factor model, Desktop model and Mini Tower model.

Does the PC boot up, just no keyboard/mouse control or does it stop at the POST (Power On Self Test) and does it give any error or beeps?

Have you tried resetting the CMOS (BIOS) Memory?  If not give that a try.  With the PC powered off, open the case and locate the CR2032 coin cell battery on the motherboard.  Remove it for AT LEAST 10 MINUTES reinstall and see if this makes any difference.  Considering the age and if it has never been replaced this would be a good time to replace it. 

If it still will not work and you have verified the keyboard and mouse are good (work in another PC) then its time to consider a new/newer replacement.  

WIN10 has that issue with borked feature updates. It appears that some hardware (ie USB ports etc) don't work when "fast startup" is enabled in the power options menu.  

Disconnect hard drive data cable then PRESS F2 to get into bios.

Sadly, it sounds like a USB controller hardware failure on the motherboard.  

I wouldn't attempt to replace the motherboard.  Only another exact replacement will fit and work and even if available it will be an old used board that you will be taking your chances with. 

There are later refurbished OptiPlex PC's available at reasonable costs and that would be my suggestion.