What lead?
There are several different ways to connect a pc to a TV and which lead you use depends on what the available outputs are on the PC and what inputs you have on the TV
I suspect you are talking about a VGA cable (it would have a 15pin connector each end) in which case, PC world are talking rubbish saying it's only for upto a 21inch TV (I have a 50inch TV with a VGA cable plugged into it)
If I have got what you mean correctly then this is the cable you'll need (note the separate audio cable as I assume you'll want sound as well as picture)
http://www.amazon.co....qid=1275558871&sr=8-6