Ipconfig renew after every reboot / sleep

have you tried assigning ip address to each device? by telling each device what address to use they will not ever have to ask the router for an address. your router should be addressed something like 192.168.0.1, or 10.0.0.1. if it is 192.168.0.1, device 1 would be assigned 192.168.0.2, second device would be 192.168.0.3, and so forth.
http://www.howtogeek.com/howto/19249/how-to-assign-a-static-ip-address-in-xp-vista-or-windows-7/
the only address that actually ever needs to change is the modem and that is done by your isp.
once you assign static ip addresses to your devices the problem should go away
 


That is pretty smart. i know how to assign each device an IP. i will give only the wired devices an higher IP. but what causes the problem ? wouldn;t it be better to solve to problem instead of chaning ip's ?
 
variables abound. could be router not supplying proper ip addresses, could be network card using another devices ip address, could be a myriad of things, but if after assigning static ip addresses you still have a problem then the diagnostics get really interesting and time consuming. I suggested this as a first step in diagnosing problem and/or as a workaround