I want to connect a camera to PC and take photos.
What cameras have this option? Most cameras, when connected to PC, seem to disable capturing when showing card storage?
Is there any software that can be used with any camera?
If you are into Linux you might wanna have a look on darktable, a RAW processing software that allows you to do tethered shooting using the gphoto2 library (most DSLR cameras are supported by this)
If you have a Canon EOS camera, then the EOS Utility software that is bundled with your camera and used primarily to download photos to the computer has a module for remote (tethered) shooting. It will let you adjust most all of the controls from the PC while previewing the scene a-la liveview.
I totally do not know if this is actually possible, but for many Canon compacts there is an alternative CHDK firmware which may let you shoot tethered as well.
You can do this with most Canon branded cameras. DSLR cameras include the software, or you can get commercial software at http://www.breezesys.com/PSRemote/. You might be able to do this with other brands as well, but I don't have experience with them.