Is Windows removed completely?
Else you can try to repair the boot partition trough a bootable windows CD.
If it formatted your entire drive (you selected this or not btw) and windows is lost, everything else is aswell and you will have to reinstall windows with, again, a bootable CD.
You can try and see if your Dell has a repair function on it. Nowadays instead of providing CD's with new laptops suppliers often take a small portion of the HDD and make a partition of lets say 8 gig that holds your windows and drivers and all the programs you deleted right after you got the laptop. So check if you have a small D: drive e.g. with files on it.
When you boot read the boot options (e.g. F2 for BIOS, F10 for boot menu etc.) try these and see if there is a repair - go back to fabric settings w/e function. If there isn't, start pressing F8 repetitavely (is that a word?) while booting to see if you get into a different menu.
If all else fail and you have no CD's, there is a sticker on the back of your laptop with a windows key. Get a copy of the same type (as written on the sticker) and install it using your genuine key.
