In the last few days a very strange phenomena started occurring in my PC:
I have a Windows 7 PC connected via a wireless network to a router.

Last week the wireless connection started to reset to Limited Connectivity (marked with a yellow exclamation mark on the task tray and the PC IP address assigned by the router reverts to 169.xxx.xxx.xxx domain).

The same router provides Internet connection to another PC running Windows XP, a laptop running Ubuntu and an Android smartphone, none of which has a similar problem.

I have tried to replace the router itself and the PC wireless card but the problem remains. 
Changing the router security protocol (WPA-> WPA2) or vice versa has some limited effect. After I reconnect to the wireless network and supplies the password (the same password) the Windows 7 PC stays connected for 24 hours after which the connection resets itself again and I have to swap the router's protocols again. Which suggest this is some software/configuration issue.

Intensive goggling did not result in any meaningful information or possible causes.

Ideas? 

**UPDATE:**

Following Azz's lead in the comment I tried to the match the mysterious reset period of 24 hours with the DHCP lease expiration. It's a total match, so the DHCP lease expires and Windows is unable to get a new one. Why is that? Why would that happen only in Windows 7?  

I am changing the question title to reflect the new information.

**UPDATE #2 - problem solved see below**