Lenovo G580 hard disk failure - how to reinstall W7 with no recovery disc?

[TheNiceGuy]

Thanks.
This one I linked
http://s.kakaku.com/item/K0000647599/
Appears to be the only one running ddr3 ram. It has 1 2gb chip, and 1 spare slot. (The others run ddr3l - is that not compatible?) From the 2 old lenovos we have 1 4gb and 1 2gb chips in ddr3. Will either work in the spare slot, or is an incompatibility issue likely?
I already checked local online auction sites for used your broken Lenovo's – they're full of pirates charging way too much so I think going use the best option.

 

[Blue_Max]

Don't pass up a good machine just to use your old 4GB stick! It'd be nice, but not worth the tiny increase in price of just getting what you need right out of the box.

Lenovo not have a Japan site to talk to a rep for a possible discount?