Will I lose free trial after doing system restore?

I got a new laptop (Acer, Windows 8.1) over the weekend and it seems to have downloaded some programmes like Wijam, Boost ads and Webshield which make pop ups and adverts appear over every website. Downloaded Norton's free trial to do a deep scan and I think I've managed to get rid of them. Uninstalled Wijam and Boost through add/remove programmes, but can't uninstall Webshield. Every time I try, Norton pops up with a notification that it has blocked a trojan.exe file. If I do a system restore to the day I first opened the laptop, will I still be able to have a free 30 day trial? Or will it recognise my email / device that has already 'had' the trial? It's just until I can buy and have the Norton CD programme delivered from Amazon. 

Thanks in advance.