successfully rooted on 4.2.2 stock ROM. being a little cautious (read: paranoid

) I tried disabling internet on the machine I was running the root program. no luck, it NEEDS an internet connection. the strange thing was that it needed to remove the drivers that windows installed 5 minutes before, and then installed its own drivers. Suspicious or not, it worked.
my experience in case this helps someone:
without internet connection, the program will not connect your device. I double checked if USB debugging was enabled, dis- and reconnected the cable but the program would NOT detect my device. Enabled WIFI on my laptop, got internet again, and it started to connect. Don't worry when this takes long, in my case it took 3 minutes to uninstall the drivers or whatever it was doing (fast win7 x64 laptop, 40Mbit internet connection).
when there finally was a connection, I just clicked on the huge ROOT button.
Then don't get worried when it says "rooting" and "testing root" several times. I'm guessing it tests several different exploits until it finds one that works. on my mobile the "rooting" and subsequent "testing root" took 3 or 4 times. It concluded with a reboot and the root software returned to the initial screen asking for a connection. I disconnected the cable before the mobile was ready again as I did not want the root program to connect to my mobile again. It seemed to take a few seconds to find my carrier information (I got slightly worried) but after 3 seconds or so there was a signal. before the root, I never noticed this delay, nor was it visible the next 2 reboots. All seems to work.