WEP Dotmatrix Printer Prints the Documents incorrectly

Hi i have one WEP LQDSI model Dotmatrix printer.When i give multiple printouts at a time we are getting wrong printouts i.e if i give a text print like “Hi How” ,i am getting print like “iJ ipx” that mean the next letter next to the original letter is printing during prinout. I tried format ed the PC changed drivers,changed the PC nothing works.Please suggest.