I used the trial version of TDS well over a year ago...I went with BOClean at the time, but now BOClean is having some bothersome CPU usage spikes that I thought were gone...but apparently are not. In any event, I cannot use TDS in a trial again (I tried but it won't let me), so I have tried out Ewido and A Squared. Ewido uses even more CPU than BOClean does (it seems to cycle every few seconds) although it does have both the on demand and resident scanning that seems to be useful. A2 has both on demand and resident and appears not to use very many resources at all. A2 also makes some claims as to it acting as a "Process Guard" type program as well. Finally to my question...in regards to memory use/CPU use, how does TDS3 compare to the above mentioned programs (with the resident memory function enabled). In addition, will it conflict with my following setup? XP Home SP2 AMD 1800 512 RAM Sygate Personal Firewall Ad-Aware SE Plus (licensed) Kaspersky Personal Pro 5 (very close to buying this one) By the way, I'm not a PC guru of any sort...so ease of use would be an added bonus Thanks for the help.