Those that were in the c:\System Volume Information_restore points (now in the chest) are only there because they were previously deleted or moved from systems or were files monitored by system restore. The file names aren’t those of the originals, but those given by system restore, but retaining the tile type of the original, .exe file type.
If there is any suspicion about a restore point then it is best out of the chest as if you use system restore at some point in the future it could possibly infect your computer. The worst case scenario is that these suspect restore points wouldn’t be available in the future even if they weren’t infected (I think unlikely), but the older these restore points are the less value they have.
Personally I would suggest that you periodically clear out all restore points if your system is clean and running normally as it can consume large amounts of HDD space.
The avast detections of HTML:Iframe malware has been very accurate and as a local file if related to Dell Solution Center it might be that the iframe in this file imports information from some other source and it could be this which is found suspicious. So it requires further investigation, see below.
The c:\drivers\audio\R 158235\Setup.exc may be related to Dell, but not in that location or in a differently named folder as I found zero hits on that location in a google search. However, a search for \R158235\Setup.exc then returns hits in the Dell folder or sub-folder of dell c:\dell\drivers\audio\R158235\Setup.exc.
So this is still suspicious and could still be infected in the drivers folder and you should check it out at virustotal also.
You could also check the offending/suspect file at: VirusTotal - Multi engine on-line virus scanner and report the findings here the URL in the Address bar of the VT results page. You can’t do this with the file securely in the chest, you need to extract it to a temporary (not original) location first, see below.
Create a folder called Suspect in the C:\ drive, e.g. C:\Suspect. Now exclude that folder in the Standard Shield, Customize, Advanced, Add, type (or copy and paste) C:\Suspect* That will stop the standard shield scanning any file you put in that folder. You should now be able to export any file in the chest to this folder and upload it to VirusTotal without avast alerting.
If it is indeed a false positive, see http://forum.avast.com/index.php?topic=34950.msg293451#msg293451, how to report it to avast! and what to do to exclude them until the problem is corrected.
awaiting your next instructions