Intel E7200 overclocking. Please help

Welcome to the forums jwnorbury!

With an E7200 and a Gigabyte EP31-DS3L you should have no issues hitting 3Ghz.
The first thing you should do is carefully read through the C2 Overclocking Sticky.
This guide will give you an excellent overview on how to overclock your system.

Unfortunately, as each system is different (even those with the exact same components) it is difficult to take a cookie cutter approach to overclocking.
I can point you towards the right settings but you will need to pin down the exact settings yourself.
As a quick cheat guide to get 3Ghz do the following:

1) In windows, download and run CPU-Z. On the SPD tab, take note of the frequencies, timings and voltages displayed.

2) Go into your BIOS and change the following fields (press <CTRL> + <F1> to access the overclocking features):

a) FSB from auto or 266Mhz => 333Mhz
b) CPU multiplier from 9.5 => 9
c) CPU voltage from auto => 1.35v
d) Manually set the RAM speed, timings and voltage as specified from CPU-Z
e) Save and exit the BIOS

3) In windows, test for stability using prime95. Keep track of your temps with Coretemp or Realtemp. Do not let them get above 75°C. If your temps do pass 75°C while under load, immediately lower the CPU voltage/FSB.

4) If, after testing for 15min-1 hour with prime95, you have no errors, lower your CPU voltage one setting and retest. Repeat this step until you begin getting errors then raise your voltage two settings. At this point, it would be best to let prime95 run for 8-24 hours to test for stability.

Best luck!

One more thing:

Go into Advanced BIOS Features and disable following options:

- CPU Enhanced Halt (C1E)
- CPU EIST Function

You may enable them later on after checking your system for stability. I have them enabled now.