Read This & learn it & you will be able to answer :
how u will give new autherizations?
how to make security authorization report?
http://help.sap.com/saphelp_bw21c/helpdata/en/5c/deaa74d3d411d3970a0000e82de14a/frameset.htm
Use SE16 for table USR02 to answer :
in which table failed users login attempts will be there?
how to see the table entry values?
field values >0 for field UFLAG means user is locked.
If you are even intending on going near a user, get some training or you could cause some real damage. SAP course is ADM940 for basic auth concept
