Not sure what you're referring to precisely since I don't use Windows, however, when people download from you and/or you're doing a lot of searches & requeries you're using up your upstream bandwidth. This means that when your browser makes a request for a page, it has to wait its turn to transmit the request and this might involve significant delays. Options >> Uploads >> Basic >> Upload bandwidth allows you to adjust this. You might also look into using a Firewall with QoS support, which allows you to prioritize particular protocols (i.e., requests from your web browser will take precedence over gnutella).