reformat..
first do u have the windows cd?
if yes then pls restart your com now and do the following:
when u start up your com, there's a black screen with words right?
press enter or f12. press alot of times not jus one time.
partition: it's like a big shelf (drive c), if u wanna organize it
u must divide it right (drive c and d)
after partition, it's the windows installation.
i reckon u to use recovery disc then format