It's bad enough that stuff doesn't work the way you want it to, but it's even worse when you format your friend's drive and you can't get it to work properly!
Obviously I was quite bothered and embarrassed because it was supposed to be a quick job so he could continue on his pc.
I looked around on Google and it seemed that other people who bumped into this problem fixed it with giving the setup a raid or SATA driver, but unfortunately this didn't make any either.
I then took a peak in the BIOS of his motherboard, an aging Gigabyte board with an nForce 4 chipset and I found that the drive controller was set to operate IDE mode, which I thought seemed rather quirky because his main and only drive was a SATA drive. I changed the drive controller to work on AHCI mode instead and thankfully after a few minutes it started expanding the files!
The rest of the setup went smooth, and Windows Update really sweetened the driver installation in the end because it managed to pick up drivers for all the unidentified devices.