Internet help?

It's not a major problem, however;  since I downloaded the free 'avast!' anti-virus software my internet has been cripplingly slow!

It's now got to the stage were i'm waiting at least ten seconds for my comment to process, after clicking 'submit' on this website.

Question is, does anti-virus software slow down internet speeds?

Also, I leave the internet running long periods of time; about a week usually; as I just leave the laptop on, occasionally plugging it into the wall for more power- Does this affect connection speeds?
A friend of mine said, the longer you leave the internet on the slower it gets?

mmmmm not sure about the leaving the laptop on slowinf the speed down, when yopu are on the desktop  press Alt, control and delete at the same time and see what process are running and how much of your CPU is being used it could be that the anti virus stuff is eating your processing power and memory up for some reason.
if so check the configuration of you anti virus stuff it might be checking your hard drive all the time.
im no expert im sure folk with more know how will put you on the right path.

Sack Avast off, get Avira Antivir here then download Hijackthis run it then select scan and produce a log, then pm me the log an ill take a look for ya!

This is my Windows Task Manager 'Performance' log as of now-

_______________________________________________

Physical Memory (MB)

Total           1917
Cached      1373
Free              64
_______________________________________________

Kernel Memory (MB)

Total             92       
Paged           62
Nonpaged      29

_______________________________________________

System

Handles                19710/40
Threads                        779
Processes                       66

---

Page Time        851M/4088M

_______________________________________________

I don't know if that means anything to anybody; but i'll run one of those logs and PM it to you, chrisarny.
Cheers lads

pm sent mate