.CAB files

Question

I have Microsoft Office Small Business 2003 and when I try to open Office or Outlook I get an error message that reads:   "a required installation file ZF561407.CAB could not be found".  It tells me to get the installation CD for Small Business Office and insert into CD drive and it still pops that error message.  I have even tried reinstalling/repairing the program and that doesn't help.  Could anyone tell me what I need to do to fix this problem.  Thx.