Help! I have been using Mountain Lion but Finder and the App Store won't load and keeps crashing even after reinstalling the OS. How do to fix it?

Question

Help please! I have been using Mountain Lion for a few weeks but Finder, System Prefferences and the App Store won't load and/or keep crashing even after reinstalling the OS. How do to fix it?
Model Identifier:     MacBookPro8,1
Processor Name:     Intel Core i7
Processor Speed:     2.7 GHz
Number of Processors:     1
Total Number of Cores:     2
L2 Cache (per Core):     256 KB
L3 Cache:     4 MB
Memory:     8 GB
Boot ROM Version:     MBP81.0047.B27
SMC Version (system):     1.68f99

Answer 1

You need to check to make sure you are actually connected to the network.  Tap Settings > WiFi >and then tap the blue ">" next to the network name with checkmark.  You should see a complete set of IP address but if the router didn't issue you an IP address properly, you will see your touch IP address start with 169.x.  If this is the case, you are connected to the internal network but not to the web.
First thing to do (while you are on that screen) is tap "Forget Network".  Then turn WiFi off.  Turn it back on and, if needed, tap Other and re-enter your network information.  If you continue to have problems, check with your IT department on Monday.
In the meantime, your laptop and iTunes can be used to purchase apps and music.  Syncing them with your touch is a great way to get them installed while you are waiting for the answer on your WiFi problem.