If you don't care about Windows, a Linux install will not require any drivers at all and everything will be recognized (even the specific function buttons). The only thing that require additional tweaking on the x220 is the fingerprint reader but I'm not planning to use it (security issues).
If it came with Windows 8 (licence or pre-installed) the key is embedded in the hardware. No need to type it in.
Also, Microsoft has a tool to download Windows 8 ISOs - no need to bother with the OEM.
What model is this? Typically all of the needed software is right there for easy download from the site, or you can often just install their System Update to and it'll offer you the various packages.
- re-installing Windows would void all warranties
- re-installing Windows would result in a non-working laptop because Lenovo drivers are not available anywhere
- I should under no circumstances re-install Windows because it would "break everything, because it's not Microsoft Windows on these laptops, it's Lenovo Windows".
So I guess the moral of this story is, if you have to call Lenovo and Mark answers the phone, hang up immediately and try again.