Can be any number of things, this is very vague, for example is this Skyping while trying to watch a Music Video? Or watching Netflix? You could be trying to do too much for your connection you have.
So first off download SPECCY and copy the first tab to tell us what sort of computer / device this is? You could be complaining about a XP Netbook, which would be a big reason why.
Second how many other devices (iphones, laptops, xboxes, everything that connects) to your Internet Access Point (the router?).
Third what service provider do you have and what does the 'contract' say your supposed to get for speeds?
Lastly does this happen ONLY when wireless? As in if you tried to WIRE your computer to the router and do skype+website (all websites or particular ones? all skype calls or just with one person it drops all the time) does it drop when wired?