How to fix connection issue- ipconfig /renew /release

Hi,

There are two Windows computers within my home network experiencing the same problem; the internet shows with an exclamation mark after a few hours and the only way I have found to fix this issue it to run the ipconfig/ renew and /release commands. This enables connection to the internet again but the problem occurs every day. There are macs using the network with no problems at all.

Any idea's on what to try?

Thanks in advance