ive just got a new lap top but i dont want to lose all my music and app from my 4th gen ipod touch how do i do this???

 

can any help me transfrer my apps from my phone to my new itunes, ive registered to get an apple id and authorized my computer but when i try to transfer purchases it says im not authorized to transfer them, does any one know away around this?????
im using a 4th gen ipod touch and the latest itunes

There are two basic ways to delete duplicates in iTunes. The first way is just to search through your music library and look for tracks with identical information. This is tricky as track information is often missing or incorrect. The easier way is to use software which automatically deletes iTunes duplicates.Over time it is almost inevitable that your iTunes library will get clogged up with duplicate tracks. We love to copy and download music and many times it has incorrect or missing information and we end up with hundreds of duplicate tracks. This really slows down our iTunes, wastes space on your computer and iPod hard drives and generally makes your life more complicated!