My computer gets slow sometimes...why?

This is my second question..and I thank everyone who answered the first I posted..However I forgot to tell you some details about my computer.

My computer(a laptop) had a problem..like 1 month ago, related with the hard disk and we gave it to the manufacturer (ACER) and they replaced the hard disk for free because we had a warranty.

I just got my laptop back about 4 days ago, and I have no files obviously, nor spyware, or viruses...ITS pretty much like new.

My dad got everything for free(antivirus, antispyware and firewall) from internet.

BUT I think he got too many programs and these are having a conflict with each other.

I have:

McAffee (free version...not the full mode)

PC tools firewall plus

ThreatFire

Spyware doctor

these are all free...so they are not complete versions....

I told my dad to get only one program with everything(antispyware, firewall, antivirus...) on it.

BUT he wouldnt listen.....

I think this is the reason why my PC is slow sometimes..

help.

My computer gets slow sometimes...why?moto guzzi

There is nothing wrong with the tools that are on the system, i would remove the threatfire and leave the rest of it, Your dad is right in his thinking, You need one firewall and one antivirus and one spyware removal tool which is exactly what you have listed above, The spyware doctor is one of the best for adware, spyware, malware and more, The pctools firewall is highly rated and is a good tool, The mcAffe antivirus is also effective, These tools will not slow your system down unless the antivirus and the spyware doctor are scanning at the same time, The spyware doctor can be scheduled to run at night while you sleep so be sure they both dont run at the same time,