Anyone have any experience with Windows Defender? Is it a replacement for antivirus software or something else to run alongside?
We are looking for something that isnt as bloated as McAfee 8.5i.
I've yet to see any use for Windows Defender, in my limited exposure to it, other than to alert me that there wasn't any recent updates on the system. The security control panel is often more talkative than the windows update system.
Personally I've always used Kaspersky Anti virus. They do have an "internet security suite", but considering the additional resources it uses over the "anti virus" option, I go for the AV. It's very fast, updates every 2-4 hours (although you may set this option to anything you'd like), and I've used it time and time again to pull infected windows installs from the dead.
Just a happy user of it, although I'm primarily a Linux user at home, I do support 40+ Windows workstations, and all of them are well protected with Kaspersky.
Windows Defender is old.
Check out Microsoft Security Essentials, which "provides real-time protection for your home PC that guards against viruses, spyware, and other malicious software. ". MSE came out in mid-2009. It's free for licensed Windows installations.
Consumer Reports rated Anti-malware program in their latest issue, and Microsoft Security Essentials is one of the top free contenders. The report is available in the June 2010 issue, article "Security software" (still on the stands now), or via a paid subscription to www.consumerreports.org.
Windows Defender is an anti-spyware program, not an antivirus program. You still need a separate antivirus program. Some computer security suites include antispyware programs, and so you may be able to uninstall (on Windows XP) or turn off (on Vista) the Windows Defender functionality if you have this threat covered in another way.
I have McAfee VirusScan on approximately 90 machines, and I know first-hand that it can, indeed, slow your computer down, but you can configure it at a very fine level of granularity. As always, performance and security involve trade-offs. The more things you want VirusScan or any other antivirus program to check, the more processor and memory resources it will use.
Hmmm, any anti-virus that is any good should hook in any access/execution made on the system for a already known signature or common exploit type. This also means that any good anti-virus will slow your processes down dramatically.
I would rather go to a different approach, disallow changes/installations outside the users directory except for approved binaries. Have the users directory in a DFS and make regular backups. Scan incoming network on know pests.
I used this method in the past in a 4k+ users network and it worked fine, but I also think I was very lucky to never had a major pest problem in the last 8 years.
I'm of the opinion that it's more suitable for home users or really small workgroup-level networks. If you're scanning all inbound (and outbound - it's your responsibility to ensure that something nasty doesn't get out of your network and on to someone else) traffic at the gateway level, have a decent corporate AV solution in place, and have implemented sensible desktop-level security precautions and web access control/filtering, then I don't really think you need it.
Of course, it is an extra layer of protection so it may give you a greater comfort zone, but one thing it is not is a replacement AV solution.
Based on conversations that I have listened to on Security Now, Windows Defender is an anti-spyware software that scans your system for known threats. It does not do any real-time scanning as many anti-virus programs do and its definition files are updated by the monthly Microsoft update. Incidentally, that is when the program is also run. I would suggest that you keep it on your system, enabled, and updated as well as run a good anti-virus program. Here is some information from Microsoft about it.