|Dell computers usually have a recovery partition. If this has been removed, or is otherwise inaccessible, try the following.|
Remove the hard drive and slave it to another computer. Backup (copy) all important data (you may need to take ownership of the files/folders). Put the drive back into the original machine and format, then install Windows.
Judging by your responses above, this is the only option left to you (other than taking it to a shop).
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