First step try on a temp. bases a Wired connection. A Wireless connection is not a good thing to rely upon for assessing Network situations since it is affecting by signals in the air (yours and the neighbors) that not under your control.
I have few Win 7 wired computers that are used through the whole day counting on Internet connection and they perform very well.
I have few Wireless too, but none is used all day (or many hours in a row) on a constant bases. For the period of times that the Wireless used it is stable within reason.
As an example, after 5pm when many neighbors come form work and start to use their Wireless, mine is Not as stable as it is during the day when very few people are around.