Firefox doesn't have built-in virus protection, but it can request your antivirus software to scan downloads.

Are you getting a specific error message or warning when you try to update your HTC software?

HI jscher2000 Not being very good with computer stuff, I am not too sure. I did have Norton Anti Virus, but the last time I took my computer to a computer guy as it was running too slow etc, he took my Norton off and installed Firefox, so I though it was doing the same job!? It is not a warning that I am getting, it just tells me to turn off my virus protection before installing the HTC sync update.

Oh, that's a general instructions many installers give to avoid conflicts. I suggest ignoring that instruction and trying to install normally. After all, can you really trust a downloaded program??

Regarding your antivirus status, it's critical to have antivirus software, and Firefox doesn't offer that feature. If you check the "Security Center" in the Windows Control Panel, it should tell you whether you have antivirus software installed and, if so, which program it is. If you don't have one, try Microsoft's free one:

http://www.microsoft.com/en-us/security_essentials/default.aspx

If you have any suspicion that your system might not be completely clean, these two tools are highly regarded for cleaning up:

Malwarebytes Anti-malware : http://www.malwarebytes.org/products/malwarebytes_free

SUPERAntiSpyware : http://www.superantispyware.com/