inspiron one 2330

i ordered an Inspiron One 2330 with English operating system (windows 8). It arrived here in Grenada, caribbean (English speaking) with a Spanish operating system. I was told by technical support that it could not be converted & they would have to ship me another computer. Which they did eventually. It arrived also with a spanish operating system. After much back & forth technical support told me they could send me the English operating system on CD however a week later it is still not here & i have two boxes containing computers that i cannot use. I queried at the time why one agent said it couldnt be done & the other said it could. 

Does anyone know if you can reinstall the operating system (If i get it) on an all in one system? If so, I have a copy of windows 7 that i purchased to upgrade my old laptop - can I just use that?

Thanks