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DADDY BOB'S COMPUTER Q & A
Questions & Answers for the Week
of
September 5, 2010
Q.
I moved my printer from one computer to
another temporarily and when I moved it
back, it didn't recognize it and tried to
install it again. What is going on here?
A.
If you take any USB device, including a
printer, and plug it into your computer,
Windows recognizes it and tries to configure
it. Then if you unplug it and re-plug it
into a different USB port, Windows doesn't
recognize it as the same device and tries to
configure it again like it was a new device.
I suspect this is what has happened in your
case. So why does this happen?
This,
explained by the USB experts, occurs when
the device lacks a USB serial number and
serial numbers are optional on USB devices.
If the device has one, then Windows
recognizes the device no matter which USB
port you plug it into most of the time. But
if it doesn't have a serial number, then
Windows treats each appearance on a
different USB port as if it were a new
device.
Now, some time back to prevent this, many
manufactures gave their devices serial
numbers, but to expedite things, used the
same serial number for all the devices.
Then, when two devices with the same serial
number were plugged in simultaneously,
things got totally confused. Windows
couldn't tell one from another.
Also, the
sequence in which they are plugged in can
also cause confusion if done differently at
different times. Remember that
theoretically, the computer can support up
to 127 USB devices simultaneously. I
wouldn't try to use that many, but is is
possible. To make things simpler, and keep
the devices from being confused, Windows
just treats a device differently for each of
its USB ports.
Now to
get back to your printer problem. In Windows
up until Windows 7, it was possible to
install a printer multiple times. You may
have notice in the printer folder, an
installed printer with the same name
distinguished only by a (2) or (3) after its
name. Unfortunately, unless the user makes a
change during the installation, the last one
installed will become the default printer.
Therefore, if your application like a word
processor is set up to use printer #1, and
the default is now printer # (2), the
printout doesn't happen.
So, what
it the solution? To correct the problem,
open the printer folder in the Control
Panel, and delete all occurrences of the
printer in question. When asked, choose to
uninstall all the drivers, etc. too. On most
computers that have been in use for a time
you will probably see more than the current
printer listed. It is also a good idea to
remove all old printers that may have been
used in the past.
Reboot
the computer to clean things up, and then,
following the printer instructions,
reinstall the printer. NOW, note and if
possible, mark the USB port that you have
used for the printer. If in the future, the
printer is moved to another computer
temporarily and then returned, so long as it
is plugged back into this same port, all is
well and Windows will not try to install it
again.
Some
people liked this ability to set the printer
up more than once as they could have it set
up with different configurations. However,
this is no longer possible with Windows 7.
If you install a printer on one USB port in
Windows 7 and then plug it into a different
port, Windows will still try to install it
again, but it automatically deletes the
previous installation preventing duplicate
entries of the same printer. |
