Cable internet very slow

over the past 2 weeks My internet connection has gone from 300kBps to 100kBps I called my IPS and they told me every thing looked normal on there end and suggested that I remove any file-sharing programs that I have on my Computer. This makes no sense being as I have had these file-sharing programs on my computer for years :angry:
I have however recently upgraded to Microsoft XP Pro from Home.
Witch one of these thing should I be looking at. The file-sharing or the Windows upgrade.

:helpsmili :helpsmili :helpsmili :helpsmili :helpsmili :helpsmili

Chances are your ISP has noticed you download alot and capped your filesharing ports so that you get reduced speed while download but will still get full speed while doing legal things. Basically if it is this get another ISP or deal with it. Also your get a better response if this was in Internet World, pm a mod and ask if they can move it.