Device Manager takes care of all your hardware devices. It is where Windows keeps all information on hardware, like what type of devices are present on the machine, IRQ ports, memory allocations, and whether a device is working properly. The image below shows what device manager looks like when it's working properly:

(image 1)

When a device is not working properly, there is usually a yellow circle with an exclamation point in it, like this image:

(image 2)

Or it may have a red X through the icon, like this image:

(image 3)

Either way, Windows is saying that the particular piece of hardware has some sort of conflict going on. Knowing a lot about the hardware can help you to determine how to fix the conflict. For example, a US Robotics modem is conflicting with a standard serial port. You know that the modem is Plug-N-Play, so that is the item to remove (using option 1 below). You want to remove the modem because, after you restart your system, Windows should recognize that a standard serial port is using the COM port the modem was using, and assign the modem to a port that is not in use.

There are two ways to troubleshoot these conflicts:

1. You can simply remove the device and reinstall it, hoping it will fix itself.

2. You can find out exactly where the conflict is, change it, and it's fixed.

There are advantages to both ways. The second way will be more reliable, but can take quite a long time. The first way is quicker, but won't necessarily fix the problem. Below are steps for both ways.

1. The easy way: The easy way is just that, easy. Highlight the offending piece of hardware, and click on REMOVE. After the item is removed, the system will ask you to restart. Say NO. Then, click on START | SHUTDOWN | OKAY. After it's safe to turn the computer off, turn it off, and leave it off for about 15 seconds. This is the best way to clear out the Registry. Turn the computer back on, and Windows may automatically find the hardware again. If it doesn't, click on START | SETTINGS | CONTROL PANEL | ADD NEW HARDWARE and let Windows do an automatic search. If this doesn't work, go to option 2 below.
2. The good way: The good way is difficult. You need to find out exactly where the problem is, whether it's an IRQ conflict, DMA conflict, or memory conflict (you can click on the conflicting hardware item, then click on PROPERTIES for an idea). The next thing to do is find out what the offending item is conflicting with, then figure out how to fix it. Options are listed below, depending on where the conflict is.

IRQ, DMA and memory conflicts: If you double-click on the COMPUTER icon (as shown below),

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you get the following result.

(image 5)

This section can help you determine what items are conflicting. If you are having an IRQ conflict, you may see two hardware devices taking the same IRQ. However, it could just as likely be the case that that particular IRQ number is not listed at all. There are two reasons why an IRQ would not be listed: Either there are no devices on that IRQ, or two items are conflicting on that IRQ, and one of those two items also does not show up on your hardware list in Device Manager. For instance, say that my computer had a serial port listed on COM 1, and a Plug & Play modem. The modem was never correctly put into the system, but it defaults to COM 1, so it could conflict with the serial port, but never show up in Device Manager.

When there is a conflict with a certain IRQ port, you will usually see a white circle with a blue upside down exclamation point on it, like this:

(image 6)

It is also possible that this image will show up on DMA conflicts and memory conflicts as well.

If the conflicting piece of hardware is Plug & Play; IRQ, DMA and memory addresses can be changed straight from Device Manager. To do this, simply double-click on the item, go to the RESOURCES tab, uncheck USE AUTOMATIC SETTINGS and double-click on the item you want to change. If Windows tells you it cannot change the item, try choosing a different BASIC CONFIGURATION.

If the hardware is not Plug & Play, remove the item from Device Manager, shut the machine down, reset the jumpers on the card, and start the machine back up again. If there are no conflicts, Windows should detect the hardware after restarting the machine.