I have my PC set up so that I can wirelessly drop files from my MBP into my PC's shared folders at any given time. However, my MBP only seems to detect my PC's wireless signal at free will. Sometimes I need to connect to my PC, but the mac won't connect no matter how long I wait. Other times, it will just appear normally. This is from the same location. Please tell me I'm doing something wrong. How can I guarantee that my MBP wirelessly picks up my PC every time?