I'm using Avast Antivirus Home edition. Its definitely a lot more thorough than Norton, McAfee, etc. in scanning the whole system and not skipping things you don't want skipped. My computer is fine...works fine, but yesterday whenI did a rescan on some stuff downloaded from our site web design company to which there is an issued warning that ‘scan it for Trojans’ but it doesn’t detect anything what does it means…
Can you post the exact warning text or a screen shot of the alert/warning as this isn't something I'm familiar with this ‘scan it for Trojans’ warning you mention.
What is the infected/suspect file name/s, where was it found e.g. (C:\windows\system32\infected-file-name.xxx) ?
Check the avast! Log Viewer (right click the avast 'a' icon), Warning section, this contains information on all avast detections.