Startup Problems - HP Compaq Presario,Presario 2100 Reference Manual

If the USB port is not working
Contact the vendor of the peripheral device for the latest USB drivers.
Check the port settings in Control Panel. Open the hardware Device Manager,
and then double-click Universal Serial Bus Controller.

Startup problems

If the notebook doesn't respond when you turn it on
Connect the AC adapter.
Reset the notebook by inserting the tip of a paper clip into the reset button on the
bottom of the notebook. Then press the power button to turn it on.
If the notebook still doesn't respond, remove the battery and AC adapter, remove
any PC cards, and undock the notebook if docked. Then plug in the AC adapter
again, and reset the notebook using the reset button.
If the notebook won't boot from battery power
Make sure the battery is properly inserted and fully charged. Check the battery
charge by removing it and pressing the pad on the side of the battery. The lights
show the charge level.
If available, try another battery.
If the notebook won't boot from the floppy disk drive
Make sure the floppy disk drive is selected as the boot device.
If you're using a USB floppy drive, use the BIOS Setup utility to make sure
Legacy USB Support is enabled. If your notebook also has a built-in floppy
drive, use the BIOS Setup utility Boot menu to make sure the USB floppy drive
is the first device under Removable Drive.
If the notebook stops responding after booting
Check whether you are connected to a TCP/IP network with no DHCP server. This
can cause a long delay at startup because DHCP is enabled. Contact your network
administrator to determine the proper TCP/IP configuration.
Troubleshooting and Maintenance
Troubleshooting Your Notebook
Reference Guide 81