I need a website/software to edit videos?

you can go to www.keepvid.com.and you tube

Websites aren't really good for editing videos, as you're dealing with huge files, and it would take forever for your computer to keep interfacing with the website every time you made a change. Instead, you need editing software. There are many options out there, each with its own strengths. On the free end, you have Windows Movie Maker (Windows) or iMovie (Mac), or programs like Pitivi on Linux. Also, not for the faint of heart, there are two open-source editing program projects in progress. VLMC, made by the same team that makes VLC Media Player, is one that's in really early stages of development - http://trac.videolan.org/vlmc/ - not much now, but keep an eye on it. There's also the beta of Lightworks, which seems to be a bit more developed, though it definitely has its bugs and annoyances - http://www.lightworksbeta.com/ They do say you get what you pay for, so if you step up a little, you have programs like Adobe Premiere Elements, Sony Vegas Movie Studio, Corel/Ulead VideoStudio, Pinnacle/Avid Studio, and on the Mac, Apple Final Cut Express. On the high end, you have Sony Vegas Pro, Adobe Premiere Pro, Avid Media Composer, and only on the Mac, Apple Final Cut Pro. Keep in mind that many of these programs have STEEP discounts for students, on sites like http://www.specialtyvideosupply.com and http://www.journeyed.com - definitely worth a look if you're a student or an educator. That's how I started with Avid Media Composer, which is a great deal for students IF your computer meets the system requirements. Good luck!

If you want to change the video format only then use www.keepvid.com and if you want to edit other parameters as well then you can use simply the movie editor is your windows built in software program and it works fine as I have edited many movies through windows movie maker.In windows movie maker you can edit movie as you wish.