messed up computer after deleting system driver

[mingoabc]

Hi, I'm currently using a Dell i5 with windows 8.

I messed up and deleted a "pci express root complex" off my device manager and now whenever I turn on my computer my keyboard/mouse don't work so I'm just stuck on the login screen.

I have tried booting with a repair disk and recovery but it doesn't seem to do anything. The only thing I have been able to do this far is get into the bios, but I have no idea what I'm doing in there.

Thank you for your help.

 

[johnbl]

Edit: you might find that a old PS/2 type keyboard might still work and let you get into your system and repair it (restore)

ouch, you might try this: go to your BIOS find something hardware related and turn it off and back on in BIOS.
This will Trigger you BIOS to rebuild its DMI pool (the list of hardware that it gives to windows). Do this with the hope
that the updated list provided by the BIOS causes windows to think new hardware has been added and forces it to run its plug and play and to detect the your lost PCI bus interface as new hardware and reinstall the drivers/registry settings to get your system going again.

assuming you did not disable plug and play (turn of auto detect hardware)