gia,
You're welcome -- searching is one of my "skills" and probably moire useful than my technical knowledge these days!
Let's hope you can get this sorted out but as a general principle I would suggest:
"Don't touch a registry editor with a barge pole unless you know more about the registry than it does ...."
They are very dangerous tools since they are the equivalent of brain surgeons without the flexibility that experience brings.
I've seen so many computers crippled by someone "tidying up the system"
Norton Power Eraser is a very powerful tool I gather -- I've never had to use it -- and if you let it do something without already knowing what the result might be then you can be in trouble, as you have found out unfortuantely.
It's not the first time that this specific has come up as you can see from this but luckily in that case it looks as if the person asked before telling NPE to deal with it.
http://community.norton.com/t5/Norton-Internet-Security-Norton/Power-Eraser-Virus-detected-Please-help/td-p/616657
but it's not just Norton:
http://forums.malwarebytes.org/index.php?showtopic=103134
But what is interesting is this link
http://www.symantec.com/security_response/earthlink_writeup.jsp?docid=2012-050914-1455-99
dealing with a specific trojan infection in which it lists what the trojan does and includes:
The Trojan then modifies the following registry entry to hide icons:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\"HideIcons" = "1"
so this is not a pure false positive; there is a reason why NPE flags that entry.
Do you normally have your desktop icons hidden? If not and NPE flagged that entry because the value had been changed to "1" instead of the default "0" (In hex code probably) then you could have been infected so the suggestion to get a second opinion from Malwarebytes (free version) is a good one.
I can think of two reasons why NPE can't change to key back to the default:
1 -- it has been locked by the malware if you have one
2 -- it is already on the default value and so it reports back it can't change it ......
Nobody ever said it would be simple .......