Yes, you do need the recovery disc - is there a boot.wim on the recovery partition?
You also need this:
DISMGUIx86x64.zip
and This:
GIMAGEX-X86-X64.zip
D/L the recovery disc iso - extract it to your HD with e.g. 7-zip.
run dismgui - browse to extracted iso\sources\boot.wim and mount it in any EMPTY folder
copy the correct bit version of Gimagex into mount folder\windows\system32
Click Unmount - com.
Put it on a flash drive - boot it up, after it finds window installation - click on it to highlight it and select NEXT - select command prompt - type GIMAGEX, then press enter.
Click the Apply tab - then for the source browse to the dell install.wim
for the destination - browse to your windows partition ( don't worry about drive letters -they are different seen from the boot media ).
Apply the image. Should only take a few minutes.