Check the 'My Computer' for an unfamiliar drive; if as most PCs, you have a C:, D:, E: listed, these are the basics; C: & D: are the hard drive (partitioned), E: is whatever optical drive you have. You may have others such as several named drives for a digital card drive may be present too. Depending on how your camera's memory is recognized, you should have a drive you didn't before. Open the last named drive to see what (if anything) it shows for folders and files. If it brings up an error message about having nothing to read, work your way forward in the alphabet and check each. Customarily, Win will add any new drives at the end of the series of named drives.       
If you find folders on a drive later in the alphabet, open them to look at the content. If you find a bunch of .jpg files, you are there.
If you find nothing, you may have to download an additional driver since the Praktica is not a real common camera, Vista may not have provided a default driver for it.