I use a combination of McAfee VirusScan Enterprise 7.0 and Trend Micros's Sysclean (I have clients that may not have internet access, or can't run House Call for some reason - also HouseCall's not perfect).
I'm not sure if the regular consumer version of VScan will do this, but the Enterprise version still has the old DOS VScan engine in it. You can copy the entire engine folder (on my system it's located in C:\program files\common files\Network Associates\Engine) to a CD. You can then copy this folder to a client's hard drive (if you run it from the CD you'll get an error because it can't save the log file) and run the DOS VScan app from a DOS window or even a DOS boot disk (of course it's pointless running it from a DOS boot disk if your hard drive is NTFS since it won't see it).
You can use the following command prompts to run VSCAN depending on what you want to do and how much time you have (I just have batch files that do this). In all cases a detailed log is saved to a text file in the root of the C drive:
VERY QUICK SCAN (just scans the root and the Windows folder - quick way to check for *most* trojans):
scan c:\*.exe c:\windows\*.exe /clean /report c:\qscan.txt
QUICK SCAN (just scans the root, program files, and Windows folders - catches 95% of all "installed" viruses but won't detect loose viruses - like ones in your TEMP Internet Files folder, or backup copies):
scan c:\ c:\windows\ c:\windows\system /clean /report c:\vscan.txt
FULL SCAN (Cleans the whole drive, but it'll take a LONG time):
scan c:\ /sub /clean /report c:\vscan2.txt
Trend Micro's SysClean is only a Fix tool - it only cleans/deletes certain viruses (mostly trojans) that imbed themselves by altering the registry. Since most modern viruses are like that, this covers most of the serious stuff, however it will not detect simpler viruses and will not do a thorough cleaning.
It consists of a single .com file and a virus pattern file. You can download the latest pattern file and delete the old one (each new file superscedes the old one, and the old one is not required).
The Sysclean tool can be downloaded here:
http://www.trendmicro.com/download/dcs.asp
The download link for the pattern files is here:
http://www.trendmicro.com/download/pattern.asp
Every month I burn a new CD with my latest VScan Engine folder (I make sure to do a manual update first so I'm certain I have the latest definitions), SysClean with the latest pattern file, as well as the latest copy of Adaware with the latest definition files (you can download the definitions seperately).
I also put the latest copy of AVG's free AV app on there as well as any Symantec Removal tools for whatever virus is prevalent, that month, and the latest copy of Pacman's Portal Startups database EXE file (invaluable for cleaning up startup apps):
http://www.pacs-portal.co.uk/startup_index.htm