So many options... what's recommended?

I've spent quite a bit of time over the past week troubleshooting a trojan with the aid of your incredible forum. I fixed my trojan problem, but during that time, I have downloaded several utilities to help me protect my computer. I now have so many, I'm not sure which I should have running at Startup/real-time. I'm reasonably sure there is some overlap that could cause conflict and inefficiency. Here's what I've got; I welcome your recommendations: Windows Firewall SyGate Personal Firewall Norton Antivirus 2005 Microsoft AntiSpyware SpywareBlaster SpywareGuard 2.2 Ewido Anti-Malware Guard TrojanHunter Guard SpyBot S&D Resident SD Helper & Tea Timer AdAware SE A Squared I'd also welcome any "get rid of that and get this instead" type of suggestions. Thanks.

For what it is worth I will tell you what I have on my machine. Windows Firewall <<< no, I have a router SyGate Personal Firewall <<< yes I use a software firewall Norton Antivirus 2005 << yes I ise an anti virus Microsoft AntiSpyware <<< I have this and use it as an on demand scanner SpywareBlaster <<< I haver this as it blocks many infections from happening SpywareGuard 2.2 <<< I use this as it restricts 1000's of bad sites Ewido Anti-Malware Guard <<< I use this as an on demand scanner TrojanHunter Guard <<< do not use but it is a good tool SpyBot S&D Resident SD Helper & Tea Timer <<< I use ason demand scanner AdAware SE <<< I use as on demand scanner A Squared <<< I use as on dmand scanner AS you can see I use most of them. I use many of them as an on demand scanners as this use no resources but does use disk space. If I had limited space these are the ones I would keep but this is a personal choice. Software firewall Anti virus ( of course keep it up to date and active) SpywareBlaster SpywareGuard 2.2 Ewido Anti-Malware Guard SpyBot S&D AdAware SE