Do you have any malware or security programs that you use on a regular basis?.

I am sure I used to run Adblock Plus with Firefox 3 But maybe I am wrong.

Next thing would be to make sure you have the latest Java and Flash updates installed and remove all old ones.

"...CPU system idle is 99%....speedtest came as 5727kbps D/L and 989 U/L...."

I agree too that those results are fine so it's not a problem caused by an overactive CPU or poor download speeds.

Insufficient RAM can seriously affect a PC's performance, so, following on from Buteman's suggestion, this will tell us if your PC's getting short of memory:

1) Open up all the programs that you'd normally have running at the same time.

2) Go back to Task Manager's "Performance" section and let us know the following information:

In the Physical Memory (K) section, what's the Total?

In the Commit Charge (K) section, what's the Peak?

Thanks for that Bexley.

Those results show us that your PC has 196MB of RAM available to Windows. However, at its peak it was using 392MB. When a PC runs out of "real memory" it starts using the hard disk to store information. That works OK but it's incredibly slow when compared to the read/write speeds of real memory. That's why your PC's performance is so bad - it's run out of RAM and is using the hard disk.

196MB of RAM is insufficient nowadays, even for Windows 2000. You've now got two options:

1) Install some extra RAM. This would be the ideal solution and it should dramatically improve your PC's performance. It would require you opening up the PC and removing/inserting a memory module or two. It's normally much much easier doing this on a laptop.

Try the Crucial System Scanner Tool. After it's scanned your PC you'll get a report showing you your upgrade options. If you need help with interpreting the results then click once in Firefox's Address Bar to highlight the address then right-click, choose "Copy" and paste it here.

You'll need to increase the installed RAM to at least 400MB although 512MB would be ideal.

Because you're running an older PC, the cost of the RAM may be prohibitively expensive but let's see what the scan results tell us.

2) If you're unable or unwilling to upgrade your PC's RAM then we could take a look at the most memory-hungry processes running on your PC and uninstall them. I have to say that we're probably going to have to do an awful lot of pruning to make your PC perky again :(

If you'd like to proceed with that then post back for more instructions.