Posted 04 July 2008 - 05:01 AM
My initial guess is that you are turning on your machine first, which is getting an IP address assigned by the DHCP Server, sometime later your Xbox or other machine is getting switched on which may have an IP address manually set to the same IP address as your machine, this effectively kicks your machine off the network until your machine applies for a new ip address. If your machine goes on after the Xbox or other pc then the dhcp server gives your machine an ip address not already in use, that is why it only happens sometimes.
Click on Start button > Run > and Type command cmd > Press [enter] key
At DOS prompt type the command:
That should let you know about how long you IP lease period is set to. If it looks about 3 days then that may add weight to the explaination.
An option could be to take the details output from that and manually set the IP address, Subnet Mask, Default Gateway and DNS Servers for your machine but change the IP address of your machine to be something in the same range. i.e. if your current IP address is 192.168.0.2 change it to something like 192.168.0.22.
If you can get into your router settings with all the machines switched on your should be able to tell which machines have what IP addresses assigned to them, just pick an address that hasn't been used before.