Some things you can try here, listed in the order you should try them.
- For wireless connections, remove all the stored wireless profiles and search for networks. You'll have to enter the encryption key again, which is sometimes the issue for connection problems.
- For wireless connections, change the channel on the router, I like channels 1, 6, and 11 in the US.
- For wireless connections, try moving either the wireless router/AP or the wireless computer. Even a couple of feet will sometimes make a big difference.
- Update the network drivers (wired and wireless) on your computer to the latest available.
- Update the firmware to the latest version available on the manufacturer's site.
- Reset the router to factory defaults and reconfigure.
Many times these measures will resolve a lot of intermittent issues.
Another thing to try for Vista is the following set of fixes.
Changes that may help to increase the compatibility of Vista & Windows 7 with older networking devices:
Disable the IP Helper service:
1. Hold the Windows key and type R, enter "services.msc" (without the quotes) and press Enter
2. Scroll down to the IP Helper service, right click on it and select Properties
3. In the dropdown box that says "Automatic" or "Manual", set it to Disabled and then click on "Apply"
4. Then click on "Stop" to stop the service from running in the current session
5. Click OK to exit the dialog
1. Hold the Windows key and type R, enter "ncpa.cpl
" (without the quotes) and press Enter
2. Right click on each network connection and select "Properties"
3. Remove the checkmark from the box next to "Internet Protocol Version 6 (TCP/IPv6)
4. Click OK to exit the dialog
NOTE: You should do this for each network connection.
Disable the DHCP Broadcast Flag:
NOTE: You should do this for each and every GUID subkey.
- Hold the Windows key and type R, enter regedit and press Enter.
- Locate and then click the following registry subkey:
- In this registry path, click the (GUID) subkey to be updated.
- If the key DhcpConnForceBroadcastFlag does not exist, use the Edit menu, point to New, and then click DWORD (32-bit) Value. In the New Value #1 box, type DhcpConnForceBroadcastFlag, and then press ENTER. If the key exists, skip this step.
- Right-click DhcpConnForceBroadcastFlag, and then click Modify.
- In the Value data box, type 0, and then click OK.
- Close Registry Editor.
NOTE2: (GUID) is a mnemonic for the individual subkeys, the actual text "GUID" does not appaer.
The only program I'm aware of that currently relies on IPv6 is the new Windows Meeting Space. The first 2 changes will cause that program not to work - but will leave all of your normal (IPv4) connections unaffected. If it causes problems that you can't overcome, simply revert back to the original settings.