1st step you should try. create a new location.

go to system preferences>network, look at the top of the window. there something call location on top (by default, it shows automatic).
click on that and select edit locations. click on the + sign to add a new location. then press on apply. restart your computer and test again.

2nd thing, tell us the IP address that u are getting. are you getting a self assign IP (169.254.XXX.XXX)??

3rd thing. Instead of trying to browse using safari. try to ping a website and see what it says.

go to Applications> Utilities> network utilities. you have an option to ping there. do you get error like unable to resolve DNS etc etc??

after all those if still having issue, easiest thing to test is to create a new user account.

go to system preferences and create a new user account. lets say if happens on a new user, then boot into the Mac OS install DVD and tried to do a ping test when u boot into the install DVD. if issue persist in the Mac install DVD = HW issue.

Try all those steps 1st. tell me after doing which step the issue is resolve, then i will guide u through how to resolve it. you can pm me with the results as i don't linger here much.

better leave the adapter connected. if u let the battery drain, it is going to eat up ur cycle count hence make ur battery depleted faster.

1st of all, i don't know what are u talking.
2nd, what macbook are u using? a Macbook air? if u are using a Macbook, why do u need external boot?

i tried to find the work around on that, but unfortunately we really can't install IE on a Mac.

what type of wireless router are you using? if you are using a wireless G router, mayb you can consider changing it to a wireless N router as it give better connection speed and also coverage area.

i notice this as well. my msn crash very often and cannot login sometimes. I guess this is smth to do with the application it self, and nothing can be done for now. I would only suggest you to keep trying. My office all workers use Macs. And we did encounter this issue pretty often.

Macbook air is just been revise recently. if u wanna wait, prepare to wait for around 1 year for a revise version.

there is no 11 inch macbook air previously. And the price for the 13 inch is freaking expensive.

how much u bought the mobileme subscription for? i got a few wanting to sell .

that is only find my iphone service, u don't get the contacts, mail, calenders, idisk and other mobileme features. and its not iOS4.2.1, its free for iPhone 4 user.

i tried it with my iPhone 3GS running on 4.2.1, cannot. So its for those new device. iPod Touch 4 and also iPhone 4. Those running 4.1 can get the service by subscribing to MobileMe