Driver for win7

sounds like drivers issue.

my pc has two operating systems, that tv card properly working with sound on xp operating system
but there is no sound in windows 7 operating system but all other pc sound working properly

Win7 is not listed as supported for that card. You'd need to contact the maker to see if they plan to write new drivers. Vista is also not supported, some devices that don't run in Win7 may run under Vista drivers, but in this case, no luck.