Ever since Windows came out there has been a bug that has never been fixed.  It is some sort of memory leak that occurs on some computers and not on others.  The sympton is the computer will lock up for no apparent reason.  If this happens to you, try this.  Install solitare (the card game) in your start up folder.  Move it to be the first startup program installed if there are more in the folder.  By doing this there will be a buffer (the solitare program itself) between the operating system and the next program loaded in memory.  Many times this will solve the lock up problem. 

 

Also if you are having a lockup problem with only certain programs, sometimes loading another program in memory before the offending program is loaded will eliminate the lock up problem.  In this second example there is something wrong with the offending program and it should be uninstalled and reinstalled to fix the problem.