Question : Problem: Memtest86+ one error 3 passes

I recently fried a MOBO and possibly RAM by putting the RAM in backwards (we won't get into that). I do not have the post backwards RAM in.  I am using the original RAM.  When I say original I mean what was in there before I blew up the MOBO.  I also have a new MOBO which is the same exact model.  I am testing the original RAM to see if it is still good.  They are a hodgepodge of RAM.  They are different manufacturers but it is the same type (DDR 266).  So I have been testing them with Memtest86+ for the past 3 hours. 3 passes have already gone by and I am currently on the 4th.  I only got one error and it was on the 4th test of the 1st pass.  The same error hasn't occurred since.  I realize any error is no good at all. But what should I do now? Is one of the RAM DIMMs bad possibly?  I have not tried them separately yet.  I also downloaded a program called HCI memtest which is a Windows based memory checker.  In some forum I read that Memtest86+ is not perfect and HCI is a better checker.  Any further advice would be fantastic.  Thank you in advance.

Answer : Problem: Memtest86+ one error 3 passes

Memtest86 is good tool and it is free! however you should test each memory to sort out which failed.