Slow internet, switch comcast box for airport express?

[kdawnz]

Hi all...
I am having some major internet issues at my house, and am considering switching my wifi to run through airport express. I'm a bit of a neophyte though, and am not sure how/if I can do this the way I'm thinking I can.

I have comcast internet right now that is connected to a box to transmit wifi to my house. My internet has been heinously slow since I bought an imac and loaded snow leopard onto my macbook. I've ruled out computer issues by bringing my macbook to work and using that wifi, whcih promptly brought it back up to normal speed.

I would like to get rid of the comcast box all together, and just connect directly to the airport express. will this work? i think it may be a good idea because we'll have 4 or 5 computers working in the same house. i was also hoping this would solve our speed problem and save me the trouble of waiting around all day for comcast to show up (they want me to be ready for them from 6AM-6PM!). of course if the speed was still slow, i would call them. also, could i get in trouble from comcast for switching boxes?

and lastly, I live in a house that's been split into a duplex. All the computers in my house are macs, but I don't know what the upstairs tenent will be running. will it be a hassle/more challenging for the upstairs neighbor to use the airport express rather than the comcast box if she has a PC?
sorry, i realise these are totally duh questions. thanks!

PS. Is this a totally dumb/waste of money sort of idea?

[rzj90059]

Try connecting your Mac via ethernet to your Comcast router if possible. If speeds are still slow then its your ISP.