DOS virus? Letter " i " does not appear while in DOS mode

My Latitude CPX Model # PPX  acts  like its got virus. Mouse keeps typing same thing over and over.

 I finally got into  Safe MODE dos  prompt.  But the  letter i would not appear screen. 

All letters I typed appeared on screen except the letter i

 Please help.  I've got data from year 2009 on that computer and software that they don't make anymore like Lotus 123 Spreadsheet Release 9.