1, is anybody els using your wi-fi connection? set up your
router with Mac address filer on. (only allows computers to connect on your Mac address list). Set up encryption and password.
this will stop people connecting to your broadband with out you knowing.
2, set up your router to e-mail you when somebody try to connect to your wi,fi.
3, which sites did you do your ping speed test?
http://www.thinkbroadband.com/speedtest.html
http://www.speedtest.net/
4, have you got your router plug into the 'master' (primary) phone socket? any extension socket will be slower than your master socket. Alway use the master for the best speed.
5, use fire fox internet browser, (faster and better than internet explorer), clear out your internet history etc.
6, a possible problem is your browser is hijacked.
check to make sure your home page is the one you set up.
run a spyware check. Do you use a good spyware program?
spyware doctor is the best one ive every used.
included free with the google pack.
http://pack.google.com/intl/en/pack_installer_new.html?hl=en&gl=us&ciNum=11
7, passable bandwidth bottle neck at your telephone exchange (only if you are on ADSL).
phone your ADSL supplier to complane, force then to fix your speed.
8, Cable? can be slow if your cable is shared, phone cable and force to fix.
does you new supplier or old supplier use:-
local loop unbundled (suppliers own kit in the exchange)
Traffic Shaping (A trick used by all cheaper providers; during peak times or heavy traffic they may cut the speed of your connection).
More info would help you get more precise answers.