Define `slow`. Slow to boot/shut down or in `normal` operation?
What BB did you get ADSL or router and was the slow down immediately after you installed the software or had you been online?
What security software have you? Have you carried out a full scan with a good anti-virus (AVG/Avast type) and scan for other `nasties` with something like Spybot/Ad-Aware/Defender?
Are there any funny noises from the HDD?
Malware is likely to slow your PC and should be the first thing you check.