Change of MS Office

Hi. On my Laptop, I'm currently using a trial version of MS Office 2007 Small Business with Business Contact Manager in MS Outlook The trial period is going to expire soon and I intend to get the MS Office 2007 Standard with just MS Outlook from the shops instead of online.

Do I have to uninstall the trial version first before loading the disc of the MS Office Standard, or can I just insert the disc of the MS Office Standard and a prompt will come up to ask me to uninstall the trial version? Do I really need the key to the trial version?

If I uninstall the current MS Office with Small Business, will the data in my Laptop, for e.g. contacts in MS Outlook and all my Word, Excel Files etc. be deleted?

Thanks for any help.