I have several dvd records wich I want to convert to mpeg2 file on my computer so I i can watch it direct on the screen without the DVD, and so i can watch them on my TV from my computer in the celler.
The .VOB files on a DVD are already in mpeg2 format -- you can check with a free utility such as 'GSpot'. Some of the (typically smaller) VOB.s may be extras included on the disc but you can easily check which ones are the actual movie. There is a standard maximum size for VOB files so a typical film will be distributed across several. The other files ie BUPs and IFOs are the data for constructing the menus and chapter stuff and can be ignored if all you want is the movie.
Some media players will be happy with the files as they are or you can copy them to your hard drive and rename them .mpg. You can of course just copy everything to your hard drive and use a computer program to play just like a DVD player.