Here is guide how to check game md5 checksum to avoid problems with your game image (ISO\BIN). The purpose of this step is to verify that you RIP is 100% correct. If a tiny file inside your ISO is corrupted or did not copy correctly you will get a mismatched MD5 checksum from it. Best way to verify if it's a 100% good rip is to compare it with the validated MD5 checksum for the game on redump.org. A lot of times the game will load in OPL, but may suffer from glitches, bugs, and other issues because it's files are corrupted. Or it'll not boot (for example black screen after OPL launch game). To avoid this, verify your ISO before going forward. Saves you a lot of time. Takes a few seconds to verify a 4GB ISO. Tools needed: ImgBurn WinMD5Free For this example, we are going to check the ISO checksum for the following PS2 game for OPL: God of War - SCUS-97399 - DVD9 1) Rip the game from Disc or DVD disc to an ISO file: God of War.iso -- best free tool IMGBURN for PS2 games. 2) go to redump.org - Link | Mirror 3) search for God of War then make sure the GAME ID: SCUS-97399 matches. 4) click on the God of War name to see more info. 5) at the bottom copy the MD5 checksum found there. 6) paste that checksum on WinMD5Free -- the tool I provided above (in red box in screenshot below). 7) drag and drop or browse to load your God of War.iso 8) wait a few minutes until it generates a MD5 checksum (blue box in screenshot below). 9) press verify, if it will tell you if it matches or not (most of the times you can see it does by a visual comparison). 10) Done. A typical DVD disc type for the PS2 when being ripped turns into a ISO file. A typical CD disc type for the PS2 when ripped turns into a CUE+BIN file. To convert BIN into ISO use WinBin2Iso: http://www.psx-place.com/threads/winbin2iso.19094/. When you convert a BIN into a ISO or VCD, you change it's properties, which will lead to a different MD5 checksum. So before you convert make sure to checksum the CUE+BIN and any other files prior to conversion.