* Reformatting a partition will erase everything on the partition, including the OS.

* You can't simply move your OS to another partition. To do anything like that you'd have to boot from another already-installed OS on a third partition or boot from a free Linux Live CD (Ubuntu, Knoppix, etc), then copy the folders over. However, this will copy all the data, not just the OS. Thus, I don't see what the point would be in reformatting the partition.

* The same thing can be accomplished using ghosting/cloning software such as Norton Ghost, copying the entire hard drive to a set of CDs/DVDs or another hard drive. Again, though, once you restore from the clone you'll be back exactly where you stated.
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Basically, why do you wish to reformat your hard drive/partition? If it's due to fragmentation, you can run the Windows Defragmenter or a third-party defragmentater to resolve the issue. If it's junk files, there are programs such as CCleaner (free) that can clean up the junk. If you're looking to clean up files you don't want others to find, I recommend something along the lines of Webroot WindowWasher. Finally, if you are trying to go from FAT32 to NTFS, that can be done from the command line...no need to do any extra work.
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For side notes, Partition Manager and Partition Magic are the two two partitioning tools available, retailing for around $80.

Also, most new computers no longer come with a set of recovery CDs. Instead, the manufacturer wants you to burn them yourself from a recovery partition on your hard drive. For specific instructions, let us know the make and model of your computer.

Hope this helps,
John