I think Memtest's website tells how to burn it to a disk. As far as the memory configuration goes I would leave it all installed and run the test. If it finds any errors then put them in one stick at a time to see which ones are faulty.
Also Vista and windows 7 have a built in memory tester. Go to the search bar and type in memory and it should come up. It will ask to restart your computer then run the tests when it boots up, when its done windows will load again.
You can also get to it the same way you get into safe mode, use F8 while its booting up I think. Then Tab to the bottom and choose the test memory option.
burn memtest86+ iso with any burning software leave disk in dvd/cd player reboot comp. if it does not boot from disk then go in to bios and set boot config to boot from dvd/cd. test one stick at a time the longer the better. I usually try to run for 5-10 passes if I want to be VERY sure. if there is errors the screen will fill with RED errors hope this helps if you need more help just ask
Test 1 stick of memory at a time when it passes 5 or 10 passes and all is ok remove that memory and put in
a other stick lets us know how it goes.it will take some time to run the test