when i run LW i can`t browse or use any of internet programm because my internet connection disapears, but LW works without any problem .... any solutions ?

Try the following:
go to options->upload->basic and set the upload speed to a sensible value.

What type of connection do you have? That might happen if you have forced resume all/most of your files. That's b/c they are all constantly searching out to find sources whilst you're dwnlding at the same time. I've had this issue. It means that your entire upld bandwidth is being taken up. Chances are people may have problems dwnlding from you also. It might also affect your connection quality. Search & dwnld techniques can help here's some hints (click on link) Immediate solution is to search the items individually, delete them from the dwnld window & reselect them from the search results. If there's too many, you might want to temporarily cancel some of them (particularly if they're less than say 5% dwnlded. You can always continue them at a later time. If this is not the issue then my appologies.