Hi Shaz, welcome to the Sony Forums 
Stills are often visible in your computer's file browser whichever way you download them, but your NEX-5 videos will be in AVCHD format, which creates a number of files not immediately readable by the computer. I need to ask you some questions before I can help:
Which image browser are you using?
Are you using a Mac?
If PC, which OS is it running (Vista, XP, Windows 7, 64bit or 32bit?)
Cheers
Mick