A theme itself will not slow down your computer noticeably. Windows Aero however might. I personally don't do a lot of heavy use on my computer, so I leave Aero on. If you find your computer very slow, you might want to consider disabling it. Here is how: Right-click your desktop and selsct personalize. Scroll down to the Basic and High Contrast theme section and choose Windows Basic. This disables Aero, and speeds up your computer a little bit. Other tips are available at the link below.
Using windows media player instead will not slow your computer down
Adobe Photoshop Elements 7 won't slow down your computer at all, unless you have very little RAM.
Your computer may be too slow, but also make sure your recording software and windows live movie maker is up to date. This may be a good sign to get a new computer.
I don't think a theme alone would slow down the Droid, but the apps you have running along with the theme may cause it to slow down.
If the Windows is messed up, then yes. It will mess the computer up.
Not unless you don't shut down windows properly. Then you might mess it up. Sometimes after shutting down improperly it will slow down windows maybe a couple of times after you reboot but often it eventually "fixes itself"
Chances are your windows registry is damaged. This can lead to a slow computer and also DLL and other windows related errors.
Yes, combat arms does slow your computer down.
If Windows 8 came installed in your brand new computer then it should run fine. If you have a lower end one then in a year or so it may not be able to keep up with the game after all the updates and may slow it down then.
No one likes a Windows XP slow startup. When you startup your computer you want it to be ready to use immediately. I can not make it that fast, but I can help you fix slow windows xp. Read more: http://slow-xp.com/how-to-fix-slow-window-xp-and-optimize-your-computer.html
Yes, they can take up a lot of RAM and slow down a computer.
Any program that runs can slow your computer down, so yes.