Kaspersky or Microsoft security essentials

You seem to give importance to performance. So i would say kaspersky is quite resourse hungry but it has good detection rate. Best way to decide for you to use the 30 day trial of kaspersky and see how you feel about kaspersky then also use MSE for some day see the performance impact of both AV then choose because every PC in this world is different both in terms of hardware configuration and Software environment, so its very important to use the use the AV in person to judge its performance impact surely i can tell you A is light B is heavy but you wont have a clue what my system configuration is or what other software i am running etc so always try AV for a few days in person and as for detection rate a good place to research is AV comparitive and Virus bulletin website go there and see the detailed test conducted by them and see which AV has done good.
AV-Comparatives - Independent Tests of Anti-Virus Software - Detection Tests
Virus Bulletin : VB100 results summary

edit: i would personally choose neither. Just my opinion

If you have Microsoft Security Essentials (MSE) and keep it up-dated its all you need. If you pay for another security system you will NOT get better protection. Instead of better protection you will pay for features you'll probably never use. Uninformed users think MSE is not as good because its free but that's just what the others want you to believe. As a former security administrator (not with Microsoft) I know of whence I speak. MSE rules!

I'm amazed people still recommend MSE! Sure it has a light footprint but, in every review I've seen over the past year or two, MSE has one of the worst detection rates. My own experience with it supports those findings. It will automatically update virus definitions only if you run a scheduled scan; other wise you have to manually update it.

Avast free is much better. It uses more resources than MSE but it much more customizable and works much, much better. It also updates virus definitions automatically and you can control how often. Modern computers are more than capable of handling the extra resource load without bogging down.

Going back to the OP's choices, I would pick Kaspersky in a heartbeat if those were the only two choices I had.

This post started almost 2 years ago in Oct 2011. Every time I read an AV comparative report, a different AV product seems to occupy the # 1 spot. There is no such thing as "the best". If there was such a product we'd all be using it and everyone else would be out of business.

Lady Fitzgerald said:

I'm amazed people still recommend MSE! Sure it has a light footprint but, in every review I've seen over the past year or two, MSE has one of the worst detection rates. My own experience with it supports those findings. It will automatically update virus definitions only if you run a scheduled scan; other wise you have to manually update it.

Avast free is much better. It uses more resources than MSE but it much more customizable and works much, much better. It also updates virus definitions automatically and you can control how often. Modern computers are more than capable of handling the extra resource load without bogging down.

Going back to the OP's choices, I would pick Kaspersky in a heartbeat if those were the only two choices I had.

I use MSE with Emsisoft antimalware Pro (real time) and Malwarebytes Pro (real time), both excluded from MSE scanning and real time and each other and my room mate tried all the 'R' and 'XXX' rated sites and MSE found malware before Emsissoft and MalwareBytes did. :) My combo with Win 7 firewall with TinyWall keeps a lot of malware off my computer. MSE finds most of the viruses by it's self. I tried other software, but always come back to MSE. I'll keep looking for a better combo.









:)

Also, there is another factor that ICit2lol missed, the ability to predict if it's malware BEFORE it's registered in the database. The ability to call on other PREVIOUS malware and decide if it may be harmful or not, this, I believe, is what makes a good AV, and that, also, is what improves detection rates.