When having "File and Print Sharing..." installed then Win9x/Me will try to participate in the master browser election. This behavior is controlled with the following values :

• Enabled : Specifies that this computer will participate with a higher priority in the master browser election, and will start an election at boot.
• Disabled : Specifies that this computer will not participate in the master browser election.
• Automatic : Specifies that if no master browser is found then it will initiate an election and participate with a standard priority.

To configure this value :

1. Right click "Network Neighborhood" and select properties
2. Select the tab "Configuration"
3. Select the service "File and printer sharing for Microsoft Networks"
4. Press the button "Properties"
5. Select the property "Browse Master"
6. Select the wanted value

This can also be done through the registry :

[HKEY_LOCAL_MACHINE \System \CurrentControlSet \Services \VxD \VNETSUP]
MaintainServerList="0" (Automatic = "2", Enabled = "1", Disabled = "0")

[HKEY_LOCAL_MACHINE \System \CurrentControlSet \Services \VxD \VNETSUP \Ndi \Params \MaintainServerList]
default="0" (Automatic = "2", Enabled = "1", Disabled = "0")

Related Description of Master Browser in the Microsoft Network

More info MS KB134304
More info MS KB150794
More info MS KB246489