Suggest you try the recovery disks method once more and see if there is a choice between 32bit and 64bit. Seems strange if it came with 64bit that it has recovered to 32bit. The recovery disks made should have taken it back to how it was when first received.
Or You can Download and burn your own set of W7 from the official microsoft DigitalRiver links on Heidoc.net Scroll down to the 2nd block and the English (USA) SP1 U (media refresh) version (x86 = 32bit and x64 = 64bit). You will have to use the product key on the sticker on the laptop and it will need activating this time over the telephone. You will also have to download from the manufacturers website the motherboard drivers and install them after you have installed W7 from the new DVD you burned. You can download the .iso onto any pc and burn to DVD to use on your father's laptop.