Mouse not working and windows wont install Optiplex 990

@TheInfinityNoob 

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Use an OEM WIN10 DVD to F12 boot from where bios F2 Sata Operation is set AHCI.

It will display Press any key to boot from DVD and you will have to hit enter before that goes away.

Choose UEFI boot from DVD.

WIN10 OEM Recovery DVD

When it asks for a key tell it you do not have a key and install.

There are no WIN10 drivers for this model however the WIN7 drivers work fine.

https://www.dell.com/support/kbdoc/en-us/000121897

Driver CAB 990 5GWVN

The cab file must be moved to my documents folder and then extracted with 7zip.

try replace 990 cmos battery with a brand new one.