Expert computer techs help please?

I have install ubuntu on my os and I didn't like it but I cant get my windows 7 home premium back please help I press f8 and no safe mode shows at all only linux can I put mg win7 hone premium disk and boot it and make a system restore from their? To few days back so I wont have to reinstall it the whole system rmember no safe mode is in the computer only shows linux I want to restore my data back and win7 please help just tell me if its possible to get win7 disk and do a system restore there or system repair please help me