Compaq Armada 7400 Reference Manual page 111

If you are running Windows 95 or Windows 98, you do
not need to turn off the computer or initiate Suspend
before inserting a PC Card.
If the computer is turned off or in Suspend, the card is not
configured until you turn on the computer or exit Suspend.
If you are running Windows NT 4.0 without CardWare
provided by Compaq, turn off the computer.
If you are running Windows NT with CardWare provided by
Compaq, you should be able to insert most PC Cards while the
computer is turned on. Contact your PC Card vendor directly for
information about the level of support they offer for "hot
insertion" with CardWare.
Before a new PC Card can be used, it may be
necessary to perform an initial setup procedure. Be sure to follow
the PC Card manufacturer's instructions for installing the needed
card-specific device drivers.