There are non-destructive partition programs out there, such as Partition Magic, but keep in mind these programs do sometimes fail leaving you with little choice but to start all over. So, if you have anything on the system you wouldn't want to lose, back it up before you begin.
I just bought an Inspiron 1564, with a 250GB HD, running windows 7 home premium.
Unfortunately, in dell's infinite wisdom, they split the hard-drive as:60gb for the main hd (where the os, my computer, my documents.... are all saved) and 220 on the second, the backup one.
I called dell, and they say.... 'reinstall windows!!!'. any advice how else to rejoin the hard drive?

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