xp booting problem

hello, i have a pc with configuartion as follows,
256 MB RAM,40GB HDD Pentium 4 1.8ghz Processor,intel 845gv mother board.
My problem is whenever i switch on the pc XP takes long time to boot.i,e The moving blue screen appears 14 to 15 times.i installed xp service pack2 also but i could’t overcome from this problem.Please anybody can give the solution?