AVG 7.5 free edition VS AVG 8.0

Avg 7.5 was a nice antivirus edition released out by grisoft .Thiswhen updated regularly removed most of the viruses that were introduced to it.It did include a small piece of the antispy software that would treat even the spyware to be a virus and remove them easily.This antivirus edition was the best until then .AVG had virus definitions updated everyday onto its site ie avgfree.com andi used to download and update them and this virus scan gave a good protection as far as viruses were concerned.But major flaw in it was it didn't covered all thespyware.

AVG then released its latest version AVG free 8.0. I downloaded it i found it good when compared to its previous 7.5 version. One major addition compared to its previous version was that it almost even blocked all the antispyware.
It seemed it was the best free edition that i ever used.After some days i found that my system was slowing down on a daily basis.I couldn't find out the reason why this was happening.
When i checked out the system processes that were running out onmy system i found that it was avg 8 that was occupy ing most of the space and it was the main reason that my computer was slowing down.
There is no problem as far as the virus removal is concerned but it slows your system rapidly.
It even doesn't have firewall that easily allows the breaching of your system as available in other Antivirus free editionslike avast.