Hello, all you good people, I have a problem with a friend's computer.

The computer runs on WinXP (Home) SP2. It is an old Compaq/HP -
with Intel celeron P4 processor of 2 GHz, with 2G of RAM, and 2 hard
drives (Drive C and Drive D) 8GB and 50GB of free disk space,
respectively.

I used his computer many times before. It was running well:
- playing music CDs (using Winamp or WMP v11 as recently)
- writing files on CDs and datafiles on DVD (by dragging and
dropping files with standard Windows Explorer)
- burning music CDs and DVD movies

But this time, the computer refuses to do anything. For example,
- if I put a brand new (blank) CD in the drive, since it does nothing,
I used 'My Computer' to look at what it says about the CD drive,
it gives me an error
'Please insert a disk into drive E:'
- same error goes with a blank DVD,
- same error goes with a commercial movie DVD (but it can open
a commercial music CD, showing me the tracks inside the CD).

I tried to attach an external CD/DVD Writer on this computer, I got
the same errors. When I go into 'Properties' of the CD/DVD Drives,
it says: for drive E: HL-DT-ST RW/DVD GCC4481B &
for drive L: HL-DT-ST DVDRRW GSA-2166D USB...
and for both : This device is working properly, and for
Device usage: 'Use this device (enable) [as opposed to 'disabled'].
DVD Region for both drives = Region 1 (and the Movie DVD used for
testing are all Region 1)

For drive E (which is installed with the computer), the Driver File
Details shows:
Provider: Microsoft Corporation
File Version: 5.1.2600.2180 (xpsp_sp2_rtm.040803-2158)
and there is not any red tick or signs of error with their drivers.

Exact same details shown for an external drive (on drive L).

It has Nero 7 in it. And nothing in Nero is set as default.

What is wrong with the settings of this computer, and how do I fix
it ?

Appreciate your help.