I updated my Lenovo laptop from XP Pro 32 bit to Win 7 Pro 64 bit.
Since then, at irregular intervals, I cannot obtain an IP address on either wired or wireless connection. When this happens, there is no connection to the LAN; all other LAN pcs work and obtain IP addresses. I see this on wired and wireless networks that are set up to provide IP address by DHCP; it is not unique to my router and access point.
I ultimately resolve it by powering down, disconnecting battery and electric power for about 1 min, reconnecting and starting up. Sometimes I go through the power cycling process several times.
I can go for several days with NO problem and for no reason I can figure, the problem returns.
I can log off my network, and come back to it later without having used my laptop and have log in problems. Sometimes, when away I log into other networks, come back and have log in failure; other times I cannot log onto other networks.
Ipconfig shows IP addresses of my LAN (from previous connection) yet there is no connection and pinging default gateway fails when I have connection issues - and ipconfig /release or ipconfig / renew fails claiming no connection.
This happened after Win 7 was installed.
When connection fails, both wired and wireless fail to connect. Assigning static IP address does not help.
Were it a driver issue, I would expect problems all the time, not on an intermittent basis.