Rizar makes a good point about programs starting up with Windows. For some reason lots of authors/publishers like to have their software behaving in this way when, in reality, for most it is totally unnecessary. Reviewing these programs and disabling any which are not needed running in the background can often lead to better overall performance.
As for your security Xterminator...AVG is currently the most resource hungry of the big 3 free anti virus programs. Furthermore, AVG no longer includes any rootkit protection. I would definitely swap it for Avast.
Comodo Firewall would also be heavy on resources (memory)...if you practice safe surfing and use Windows firewall or have a firewall included in your router/modem it is something you can do without.
As for Spybot and Ad-Aware, well both those apps have seen better days. Even though they do not consume many resources they are also not terribly effective. Either Malwarebytes Anti-Malware or SuperAntiSpyware would be better choices to have on your machine...purely for on demand scanning.