Excellent summary of first line defences from
SoftTop. As I'm sure a lot of others that frequent this forum are, I'm often called on by friends and rellies to 'have a look' at their PCs and in most cases, these measures fix or greatly improve the situation. I'd recommend the combination of a good AV application plus at least two decent Spyware apps (like SoftTop I'm assuming you are running Windows).
AdAware and
SpyBot are effective. The secret to this is a regimen of regular updates and checks - weekly is good.
If this has not fixed the problem, then you'll need to inform your ISP of the BT Speedtest result (if you are with a BT-partnered provider, this is the only one that matters; the others are inherently unreliable and can only ever be indicative). A screenshot may be helpful. Other things you can try (which may help your ISP):
Pings/Traceroutes - your helpdesk should talk you through this and give you an IP address to interrogate, which may reveal faults in their infrastructure.
Exchange hardware - with the increasing take-up of broaband, BT exchanges can and are reaching their capacities - BT are trying to keep on top of this with a rolling programme of upgrades, but delays do occur. check your local exchange
here for any known issues.
Connection condition/Latency - sign up
here (free) and follow the instructions to get a rolling, daily graph of the state of your connection - very techie but can help your ISP detect problems. Downloading your graph and sending it to them may be helpful. Hope you get it sorted.
PS - another thing to try is to ask the helpdesk what the optimum MTU setting is for their service. If you don't know how to adjust this, they should be able to tell you.