NEC laptop error

Hello,

i just recently updated my cousin's laptop from windows xp service pack 1 to service pack 2.... after that i got an option to update it to service pack 3 which is what i do...... on the update history i found out that i failed to install service pack 3 and so because the laptop hang up i decided to remove the battery then returned it so i can start again the laptop... after that with widows xp service pack 2 i previously installed i removed the itune 7.1 and quicktime then restart the laptop...... and that's when the problem began.... when i restart the laptop after the windows xp logo appears the laptop loads very slow and then when it finally open, aside from the slow loading, the task bar doesn't appear even the wallpaper didn't appear and when i open any icons on the desktop either the my computer or others the title bar is like title bar when your using windows 98...... and additional info its made in japan and if i didn't resolve it IM IN VERY BIG TROUBLE SO PLEASE HELP......