Having trouble getting your wireless network up and running? We'll show you some of the more common mistakes users make when configuring them. We'll also explain why you might not be able to use America Online Instant Messenger (AIM) service on your office PC.

By Ron Pacchiano

Q. I'm trying to set up a peer-to-peer wireless network between my desktop and laptop computers. One is running Windows 2000 Professional with an Orinoco Gold card and the other is running Windows XP Professional with a 3COM card. Both cards look like they're configured correctly, and both are showing up as working properly in Device Manager, but they can't seem to communicate with each other. Although an icon in the status bar says I'm connected, I can't ping from one machine to the other. Any suggestions you have would be greatly appreciated.

A. Before we continue, I want to first point out that despite the fact that the status bar says you're connected, there's still a good possibility that your network isn't configured correctly. All this indicator really implies is that the card can see the presence of another wireless adapter or access point. It doesn't mean that it can communicate with it.

With that being said, you didn't provide us with any detailed information on your network configuration, which makes it impossible for me to tell you exactly what the cause of your problem is. However, there are a number of tips I can recommend that should help resolve your problem.

The first thing you should check is the basics. Make sure that both computers are members of the same workgroup. Next, you'll need to double-check your IP settings. In a Peer-to-Peer environment like this without the use of an access point, you should make sure that both PCs are using a static IP address and that both are sharing a common subnet mask. A typical example for this would be to give PC1 an IP address of 192.168.0.2 and PC2 an IP address of 192.168.0.3. 192.168.0.1 is usually reserved for the Router/Gateway address. Then each PC would be given a Subnet mask of 255.255.255.0.

With that done, we now need to take a look at your wireless settings. Since you're not using an access point, check and make sure both wireless network cards are in ad-hoc mode rather than infrastructure mode. Since most cards default to infrastructure mode, this can be a common problem.

Now verify that both wireless cards are configured to use the same wireless settings. They should share a common SSID (just like the workgroup name), and they should be transmitting data on the same channel. Adapters made by different vendors sometimes default to different channels which would prevent communication.

All levels of WEP (or WPA) encryption should also be disabled for the time being. While I understand that you want your data to be secure, WEP can be extremely problematic to configure; particularly from cards made by different vendors. Once you have connectivity between your two systems, then you can worry about getting WEP to function properly. When you do finally enable it, take your time and ensure that the WEP settings on both cards are set to the same encryption level (64bit, 128bit, etc.) and that they are using identical encryption keys.

If you follow these steps carefully, you should find yourself online in no time. Good Luck!

Q. I have been using America Online Instant Messenger (AIM) on my home PC for the last few years now. Over the years I have put together a rather large contact list, many of which I use for everyday business. I thought it would be helpful to have access to them while I was at the office. So I tried to install AIM on the PC at my office, but I just can't seem to get it to work. I believe I installed it correctly, but no matter what I try, it still won't connect to the AIM service. My Internet access and e-mail all function fine, so I know it's not my connection. What am I missing, and what do I do to get around this problem?

A. To accurately solve these types of problems it is always beneficial to send us as much information as possible. Some specific information about your network environment and perhaps a copy of any error messages you might have received would be extremely helpful in solving this problem. In spite of this, though, I think your problem is straightforward enough where I can offer you an explanation for your current difficulties.

Since you're using AIM on your home PC without any problems, I think it's a safe bet that you've also installed it correctly at the office. Furthermore, since you have access to the web and e-mail, we can also rule out any problems with your Internet connection. This strongly implies to me that your company could be using a firewall to block the ports that AIM broadcasts on. If these ports have in fact been blocked, all communication to AIM would be disabled.

This isn't an uncommon practice in corporate environments. Many companies have strict firewall and security policies in place and seriously frown upon employees installing software on their workstations without first gaining authorization from the network administrator. An application like AIM is typically blocked by the company firewall for a variety of reasons. In addition to being a potential security risk, applications like AIM have a tendency to completely drain employee productivity levels.

However, if you could prove to your company's network administrator that you have a business need for the AIM service and get permission from your manager to use it, I'm sure he would be willing to open up the necessary ports on the firewall for you. AIM actually makes use of three of them. For outgoing traffic it uses TCP port 4099, while incoming traffic comes in on TCP port 5190, and AIM Images travel over port 4443. Once these ports have been opened, you should have no problem getting access to AIM from your office PC. I hope this helps!

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