Ok since no one has answered your other thread either I will bite.
Your 770 should not behave like this, mine will find 4 APs at work and at home will get 10+ and every time it researchs it will change out the weak ones for others(my apartments have free wifi with tons of overlaping APs) but you should get very good signal with just a few. You might look into cordless phones interfering.
Have you reflashed this 770?

To answer some other questions from you other threads
You can not install windows media player >> OS 2008 can play wma's but none of the 770's OSs can, sorry.
It is pretty hard to connect a flash stick to your tablet, easier with a n810, you have to get adapters and install usb control software, but you should just get a 8Gb card and carry the cable then you have it covered.