[file name]contained a virus and was deleted"

I have a two computer network protected by a Sonicwall firewall. About a week ago I was on the internet and a virus warning popped up from my then installed security software Zone Alarm. Afterwards, my connection to the internet was lost but on one machine only. After much work, I restored internet access but had to delete Zone Alarm. From the time I restored internet access I have not been able to download ANY file without getting the message: "[file name] contained a virus and was deleted". In addition to IE9 that I normally use, I tried Firefox and Chrome with the same results. I've explored the options for security settings and have tried them all, but since ALL browsers are affected, I suspect a virus. I tried to reinstall Zone Alarm, but it immediately stopped my internet access again, so I uninstalled it. Note TSG still thinks it's installed.


OS Version: Microsoft Windows 7 Professional, Service Pack 1, 32 bit
Processor: Pentium(R) Dual-Core CPU E6700 @ 3.20GHz, x64 Family 6 Model 23 Stepping 10
Processor Count: 2
RAM: 3293 Mb
Graphics Card: Intel(R) G41 Express Chipset, 1422 Mb
Hard Drives: C: Total - 476837 MB, Free - 442073 MB;
Motherboard: MSI, G41M4 (MS-7592)
Antivirus: ZoneAlarm Antivirus, Updated and Enabled