how i will do my hard disk another drive recover data without format?

anybody tell me,
i have Samsung 160 GB sata hard disk. i create 3 drive partition ex: C drive, D drive and e drive. Now i have a serious problem.i will install xp sp2 but i do not open D drive when i open a D drive then they give me a message: format this drive. But i do not want to format this drive because i have more important file on my d drive.
so advise me,what i will do now?
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