Conflict error when booting up computer

When I turn on computer to boot up, it starts out by showing the countdown of the Rams--then gives message--conflict error in Bios slot 3--I believe that's it--then it stops and gives me options of clicking F1 for setup or F2 to continue.  If I click F2, computer will then open up after showing several errors, which I cannot read as they go too fast--then computer comes on.  I also can not defrag. computer--it just keeps starting over and there are no programs running.  I know NOTHING about computers--should I just reformat the whole system with disc that came with computer?  It's HP running 98.