Dell XPS 15, installed new hard drive as original broke, can't get OEM Windows 7 Home x64 anywhere

Hi

My 4 year old XPS 15 hard drive failed, I bought a replacement. It is now installed but I can't find anywhere to download Windows 7 Home Premium x64 reinstall. I never created a recovery disk and the laptop never came with disks. I'm in Ireland so can't request disks from tech support, any advice would be appreciated. Thanks