Hey Dude, how's things in Jolly auld England?
Not so good in the broadband department, I guess?
Well, if your connection is coming to you via the old phone company, you may be in for many disappointments. All phone signals are Multiplexed, so many people can use the same phone lines. With a lot of people using the lines at the same time, voice travels OK, but data really takes a hit.
Some packets of data may have to resend a hundred times before it comes through correctly.
Cable is only slightly better. I have a Cable ISP with 5meg download rate, but at certain hours of the day, that can diminish some.
But, on the other side of the coin, if your computer is being a DOG, it won't be able to properly process data and your interpretation will be that your Broadband connection is failing, when maybe it really isn't.
We've spent hours and even days here telling people how to optimize their PC's for maximum performance. Most people don't even believe me when I say that I can double the performance of the average Windows computer.
(if I have about two to three hours at the keyboard)
In a nutshell, start by shutting down everything that you have running in the background. The worse offenders will be found in your Startup folder in MSCONFIG. Believe it or not, I have only two programs starting up on boot.
My AVG anti virus program and my UPS Monitor Program. That's really all I need. All those reminders, schedulers and updaters have NO place in a busy PC at all.
Next, you can gain a small amount of performance by shutting down all those obnoxious background Services, that windows installs.
I shut down about twenty on XP and almost 40 on Vista, without loosing any critical services that I need to do my daily business.
See the "Black Viper's" web site for a full list of Services and which ones can be "SAFELY" shut down, or put into Manual mode, so they only run when needed.
Then there's the RAM. Seldom seen and little understood, the ram is actually the very heart of your system performance.
All Programs run in the RAM, not from the hard drive.
( or, at least, that's the way it's supposed to work

)
For top performance of any XP PC, you should have three gigs of ram.
For Vista (any version) your should have four gigs of ram.
DDR2, Dual Channel, is best.
Even with enough ram, Windows is designed to use space on the hard drive called a "SwapFile" on "PageFile" which it uses as space to supplement ram.
A hard drive may be as slow as 1/1000 the speed of the ram, so everything you can do in ram instead of the PageFile is to your advantage.
And then, since Windows is using Hard Drive space to supplement ram, it would stand to reason that you should keep your HD as clean and defragmented as possible.
I have my own PC and all my customers PC's set up for a Weekly (not weakly) HD maintenance routine.
That routine includes my own XPCleanup batch file and the Extended Windows Disk Cleanup program followed by a full defrag.
* always clean the garbage out of your HD before running Defrag.
OH, if only I could just jump in my Lear Jet and buzz over there. I'd have that PC up and running like a scalded dog, in no time at all.
Then we could stop by the local pub for a pint.
Cheers Mate!
The Doctor
PS: You said nothing about your PC or what version of OS you're running so we're left to to a lot of guessing.
What OS?
How much ram?
What CPU?
What HD?
And, anything else you can think of.