Hi Please help before I lob this outta the window

Im running a windows xp desktop and having troubles when trying to play yahoo games,after downloading java i had two probs one was i was running in safe mode,im now out of safe mode and...
Hi
Please help before I lob this outta the window

Im running a windows xp desktop and having troubles when trying to play yahoo games,after downloading java i had two probs one was i was running in safe mode,im now out of safe mode and running the comp normally the other thing was it says i might need to do is run windows installer again..heres where i have the problem! where or how do i run windows installer? I just aint got a clue folks,and would very much appreciate any help for a newbie. many thanks Shaun.