Long story short, whenever my pc powers up, wakes up, un-hibernates etc, my network adapter takes at least 5 minutes to establish a hardwired connection to my router (and subsequently the internet).
Details: I've got a less than 1 year old Cyberpower PC. It's not a slow PC. Windows 7, 8GB ram, Intel Core i5-3570K CPU, Realtek PCIe network adapter. My 2 year old $400 laptop connects with no issues over wifi and on the same cable. There is nothing wrong with the router (Asus RT-AC66R), and nothing wrong with the Ethernet jacks and nothing wrong with the cable. Also, it used to connect just fine. In addition, the same problem exists in "safe mode with networking". I have also updated my network driver.
Symptom Specifics: I get connected to the network in 5+ minutes Whether or not I log in. If I do log in, the CPU takes 20-30 seconds to drop below 1% usage. The network and sharing center shows no connections at all. after 5+ minutes, I see it connect to the network, and 2-3 seconds later, the internet. If I pull up chrome, it is unable to connect to anything including the router's config page until the network and sharing center shows the connection.
Request: How can I debug this and determine if its a hardware problem or a services or a windows problem and determine how to fix it.