AVG is constantly detecting trojan horse LOP.D C and A, which I'm sending to virus fault, but I have no idea what to do next nor have I any understanding of this virus, please help?

Does not AVG offer to quarantine it; if it cannot actually kill it etc.?

it offers to heal or send to virus vault! at first I was clicking on heal but when i read help it says windows reccomends sending to vault! made no difference either way, still detecting constantly ?

Try running AVG from Windows Safe Mode and see if it can take care of it. Also you might run some online virus/malware scans or use (updated) Spybot Search and Destroy and AdAware, possibly from Safe Mode also. Online malware scanners You might also post a question in the security section of these forums.

try doing a google search using the trojan name & the words " trojan removal"...but 1st, you have to get the correct name for the trojan. I didn't find anything called "LOP.D C" but I did find plenty of varations of LOP

Ahh... once it's in the vault, delete it from that location; then rerun scan. Likely as not its the vault stored version it's finding.. Also if ME has the system restore option - can't recall if it has or not... - disable it first, then delete the vault stored item; then reboot; then run scan again. Once system is clean, re-enable the system restore option. A while back went thru' the same loop as you appear to have (with antoher a/v util; followed the path immediately above and it all went away... Still afterwards won't hurt to run an on-line scan too (Trend offer good one; takes a while...). and also a full mal/spyware scan etc. as already advised by Leroi

It does have restore and you must turn that off before scanning . Turn restore off , reboot machine and let avg run , this will get rid of it or quarantine it where you can get rid of it .