After you have installed drivers for your hardware device, the computer has encountered a problem. What is the best thing to do FIRST?

A.
Rewrite all the lines in the CONFIG.SYS or AUTOEXEC.BAT.

B.
Check if the hardware device is plugged in properly.

C.
Reboot using the Last Known Good Configuration.

D.
Reinstall the operating system.

Explanation:
Whenever you install drivers for a hardware device, the installation program will ask you if you want it to modify the CONFIG.SYS and AUTOEXEC.BAT for you or if you would like to modify the files yourself. When the installation program modifies these files, it makes duplicates, or backups, of them just in case the drivers it installs cause problems. These are the backups that can be used in this case.
Incorrect Answers:
A: Rewriting the lines in the CONFIG.SYS or AUTOEXEC.BAT would be unnecessary when all that has to be done would be to reboot with the backup files.
B: If the hardware devise was not properly plugged in it would not even go on in the first place. It is obviously plugged in properly already.
D: It is not necessary to reinstall the operating system as the best action that can be taken is to reboot with the backup files.
Reference:
David Groth and Dan Newland, A+ Complete Study Guide (Second Edition), Sybex, Alameda, CA, 2001, pp. 390-392