There are many options like Kaspersky, Avast, Avira, Eset.etc, you can choose based on your requirement and one more thing might be you know that Window defender is automatically disabled once you install a third-party security app and turned back on once you get rid of it.
I use symatec endpoint protection client. AV, anti-spyware, anti-malaware, integrate with windows firewall and anti-intrusion module. Work very well, system remain fast and until now no problem at all.
Using ESET Endpoint 5 and Comodo Firewall 6.3 here, all appears to be working smoothly. I was running the last build of Comodo Firewall 5 but had to finally ditch it when I updated from 8 to 8.1 as it was not compatible anymore. But Comodo Firewall 6.3 is much improved over the earlier builds of 6 which were buggy. Only reason I'm using ESET Endpoint over NOD32 Antivirus is because of the updates mirroring and server feature.
I tried to run WSA (webroot secure anywhere), but within minutes I'd get bsod. Uninstalling it fixed my problems, however it seems I must have down something wrong as Dark Knight got it working. Just wanted to share my $.02
Hi, Kaspersky Internet Security 2014 works fine on my Windows 8.1 PC. No Problem whatsoever . Thanks, Manu