The first thing to do if you are experiencing Adhoc network problems is to check for software updates. Just visit the manufacturers website and see if new software is available.

Most manufacturers supply free downloads via their site. More often than not the version that came with the Wi-Fi network card is well out of date by the time you bought it.

Here are some solutions to common Adhoc networking problems.

Problem: Getting a adhoc network working from a USB adapter
Having only USB 1.0 on the computer can cause problems with adhoc network card. Either add a USB 2.0 card to your computer or install an internal network card.

Problem: You have a connection but can’t browse

Make sure you have enabled Internet Connection Sharing (ICS), This must be turned on to get it to work. ICS is not the best program in the world and a free product called AnalogX proxy server is a much better program.

Setting the IP addresses to static is also a good idea. Having them set to DHCP can cause it to take a long time when finding an address.

Also make sure your firewall is allowing browsing on port 80. Try turning the firewall off and then trying it. If it then works with the firewall disabled you need to allow other services such as SMTP, FTP ect.

If you are using PPPoE as your internet connection, make sure your PC has the right MTU network settings. Start by finding your gateway address in your client computer.
Go to the Start Menu, go to Run and type in CMD, next type in IPCONFIG.

Now type in: Ping -F -L 1500 xxx.xxx.xxx ( replacing the xxx.xxx.xxx with your gateway address)

If this causes you to receive an error next try : Ping -F -L 1450 xxx.xxx.xxx
You need to get a ping response and your setting need to be as close to 1500 as they can. So keep changing the number from higer or lower until you find the one that gets you as close as you can.
If you get a ping response from 1500 this will not work for you. Once you have found it you need to change some things in the registry.

Goto
Regedit/HK_LOCAL_MACHINE/SYSTEM/CurrentControlSet
/Services/TCPIP/Parameters/Interfaces

You then need to create a new DWORD value. Call it MTU, then double click on it and pick the decimal option. Next enter the NTU number you discovered earlier.
Problem: You have a connection but the speed keeps dropping

Try slowing the connection down. Select B instead of using G will make it go from 54 to 11 mbps.

Conclusion

Adhoc networks are not the best way to network. With routers becoming cheaper sometimes they are not worth the bother. They are normally slower and have the disadvantage of needing to keep the host computer on for the other PC’s on the network to go online.