Ok i did that, I burned iso and the mds on seperate disc, and i am using maxell 8x DVD-R and SM 3.3, but nothing comes up keeps telling me not a valid ps2 disc, so i am going to work with alittle more, but help would be apprectied.
No,No,No. You don't burn them to seperate disc, Heres how to use DVD Decrypter,well you have all the right tools and its easy with DVD Decrypter.
Quick way to copy a game. Assuming you have the original game dvd and want to back it up.
step#1
open dvd decryptor then go to MODE>ISO>READ and then it will copy the game and make an iso file on your pc hdd.
Step#2
when that finishes go to MODE>ISO>WRITE and then select the mds file(It's the smaller of the two files) By selecting the mds file all your are tell DVD Decrypter to do is burn the iso file I know it sounds dumb,But trust me. It will burn the iso file to the dvd and presto you have your ps2 back up and your done.
oh, and I would not read or write over 4x or the game my skip or have bad audio, I like to read at 4x and burn at 2.5x. Try to burn at the lowest speed you can,It may take more time, But (TIME IS TO PERFECT) AS (FAST IS TO COASTER) word of the wise.
ok i will try it again but if all fails i'll leave it on my external tell i figure it out, i just got back from the store so i am going to re-decrypt and then burn...
going to try with dvd + R
Also thank you everyone for helping me figure this out!