I have used this program to protect my Windows machines from adware, viruses, and rootkits for many years and am a highly satisfied customer. Detection Rate Once, it did not detect a trojan that I was told that I had, but oddly enough, actual trojan detection programs did not find it either. Other than that, the program has kept my Windows machines clean for years. Ease of Use I was able to use this program as a newbie, and its instructions are straightforward. Scan Speed It's not all that fast, but not so slow that it takes a half hour. But I do use large hard drives, so i expect the program to need time, and I do want ti to do the scan correctly, so I don't mind a few minutes of necessary time. Availability of Updates I seem to get updates pretty regularly, which i take as a good sign that the program will continue to recognize new threats. Compatibility I have not as yet heard of a version for my Macs and definitely none for my Linux computers, but if I use WINE, I could then run Spybot when running Windows programs under Linux. Spybot runs on Windows XP through 8. I have since upgraded to Windows 8.1, and did not at that time find a version that runs on that system, but I hope to soon.