If you want to enable the XMP profile for your RAM then you need to get into the BIOS.
Go to the Overclocking TAB. Go down to Memory-Z, In that you will first see the Memory SPD. That will display the XMP Speed to you and the timings, just make a note of them.
Now go all the way back to the Overclocking Menu, go down to the DRAM Frequency and change it from Auto to the XMP Profile Value.
Check to see if the Adjusted DRAM frequency now shows the XMP profile value..
And that's it.
Here's a screen of mine with the Phenom II 965BE
For the memory related BSODs, yes, I second the suggestion of trying one stick at a time and seeing if you get BSOD's or then by running Memt download Memtest, as suggested. Change the DRAM Profile to XMP and then run Memtest to see if the problem has been solved.
After that , if it still exists, the problem, you can start by setting the BIOS to default values and with One stick of RAM, test the rig, till you reach a defective one.