Hello badboi and welcome to the Forum. Does your computer have a separate PDF reader installed? It's my understanding that Windows 7 does not natively support pdf files. A few free sources: Adobe - Adobe Reader download - All versions
(fairly bloated) Foxit Software - Foxit Reader for Windows
(tries to install toolbars, etc read install instructions carefully) Nitro PDF Reader
(my free reader of choice)
There are other free readers available so I'd suggest installing one, see if your preview issues are solved, then play around with a few until you find your reader of choice.