Advice on beefing up security against rootkits, file injectors, and ransomware

i have xp home,sp3,ie7,nis2009,mbam & sas on-demand,spywareblaster 4.2.  i’ve been reading about processguard bydiamondcs, surun, and windows steady state. any suggestions or opinions? nis2009 has done a great job, just looking to bolster defences.  thanks