help needed, computer wont start

[psidevil98]

I have a problem that deals with changing the XP bootscreen....I downloaded my bootscreen from a website, replaced the ntoskrnl.exe (i think thats what its called) in safe mode, and when i tried to restart my computer, i got a choice of what i wanted to start my computer in.  This was not unexpected, and i chose "Normal mode".  But when i pressed enter, the computer just froze on that screen.  i tried this numerous times, then decided to try the other options.  When i try it with safe mode, rows of words appear on the screen as they should, but it stops at something called multi(0)disk(0)...............\WINDOWS\System32\DRIVERS\agp440.sys.    please help  http://images.thetechguide.com/forum/public/style_emoticons/<#EMO_DIR#>/sad.gif\' class=\'bbc_emoticon\' alt=\'\' />

[psidevil98]

http://images.thetechguide.com/forum/public/style_emoticons/<#EMO_DIR#>/unsure.gif\' class=\'bbc_emoticon\' alt=\':unsure:\' /> Oh yeah, sorry, forgot to say...if u have any idea how i can get my computer working again, please post a reply and email me (ferret7654Email Removed).  I may not be able to keep checking back at this forum for a reply  http://images.thetechguide.com/forum/public/style_emoticons/<#EMO_DIR#>/biggrin.gif\' class=\'bbc_emoticon\' alt=\'\' /> .  Thanks a bunch!!!  (oh, and by the way, this isnt the same computer thats broken  http://images.thetechguide.com/forum/public/style_emoticons/<#EMO_DIR#>/biggrin.gif\' class=\'bbc_emoticon\' alt=\'\' /> )