Unfortunatelly nowadays you need a lot of security software to protect your PC.

Security Software
Firewall: ZoneAlarm
Antivirus: Antivir, [free version] or AVG (Anti-Virus Grisoft)
AntiSpam: mailwasher [not free anymore!]
Spyware remover: AdAware & Spybot - Search & Destroy
My favorite server software is the open source combination:
OS: Linux
Webserver: Apache
Serverside Script Language: PHP
Database: mySQL

For listening
MP3 Player: WinAmp,
fav plugins: SidAmp v1.33 for playing Commodore 64 SID tunes (High Voltage Sid Collection);
fav skins: QUAD 33 Series Skin v1.0 & NUCLEO N-Log v2G BioSkin®)

CD Grabber: Exact Audio Copy (EAC), works with freedb.org
use EAC with LAME MP3 coded

Browser: Firefox + extensions:
Make Firefox faster (haven't tried it myself yet!!!!)
FTP Client: FileZilla
Archive Utility (like WinZip: IZArc, freeware that suports many archive formats