Microsoft Standalone System Sweeper (link dead, sorry) is a free download from Microsoft for malware scanning from a boot cd or USB drive. It works with XP (SP3) and Vista/Windows 7. That's a handy tool to have in your pocket.
I'll start with the complaints. There are only two or three, really, which is actually almost a compliment when discussing Microsoft programming: usually there is much more that annoys me.
No ISO image
First up is the lack of an ISO image. Oh, the software you download can create an ISO, but that's an "advanced" option. To get that ISO, you have to run the executable in Windows.
I do understand the reasoning here: most Microsoft users wouldn't have any clue what to do with an ISO. There are possibly even people reading this who drew a blank on that TLA. So, sure, give the helpless the tool they need.
But did the programmers even think that there might be circumstances where a person in need of this tool doesn't happen to have access to a working Windows machine? Did they stop to think that it might make far more sense to burn that CD or flash drive from a non-Microsoft operating system?
No, of course they didn't.
One XP system I tried needed to download an IMAPI update - my bet is that it only needed that because of the option to create a bootable flash drive - surely not to write a CD?
The second gripe is the memory footprint. This tool requires 768 MB. I know that in todays world of sloppy programming, that must seem quite Spartan, but reality is that there are a lot of 512 MB XP boxes out there, and they may be the systems most in need of scanning.
But that's just a gripe. The complaint is that if you carelessly run this on a machine lacking that amount of memory, it will fail mysteriously. That is, it won't tell you that you lack sufficient RAM, it will simply fail with hexadecimal error codes. Worse, I got two different codes: 0x80072ee7 when it couldn't connect to download updates and 0x8050800c after it managed to download new data definitions. Looking up either of those would never cause you to believe you simply lacked RAM.
The first thing this wanted was to download updated malware files. Gee, why couldn't you have done that before writing the CD? Also, why does it refuse to do anything unless it gets those updates? Isn't scanning with out of date information better than not scanning at all?
By the way, if you do have to download updates manually, the file you apparently want is mpam-fe.exe. That's the Security Essentials update. They send you to the page where that lives, but don't bother to tell you what to get.
But it is fast
I ran this against a 32 bit XP with almost 300,000 files running in a VMWare virtual machine configured to use one CPU core on my five year old 32 bit Macbook Pro. It finished in an hour and fifteen minutes with all that working against it. Honestly, i was expecting it to take all day - maybe more. On a real machine with decent hardware, you might be able to go have a cup of coffee and find this finished when you returned.
It didn't find anything, by the way. That's not surprising; I rarely use that system.
So, aside from the fact that this is useless for 90% of XP systems I see in the field (because of the memory overhead), it's fast and looks like it does the job.