There are a few other versions of this error doing the rounds, such as:

• 'svchost' has been built with an evaluation version of {smartassembly}, which has expired on Wednesday, 20 January 2010. You need to purchase a license of {smartassembly}.
• This application has been built with an evaluation version of {smartassembly}.
• Etc.

The dates vary, and aren't always reported in English, although that very much depends upon where you are, but the message probably appeared in a dialog box looking a bit like the one in Figure 1 below:

Figure 1. The error dialog showing that there's trouble at mill.

You've probably already worked out by now that this isn't a good thing, but first, let me assure you that you, as an end-user, most certainly do not need to buy {smartassembly}. We make it and we ought to know.

The bad news is that this means that your computer is infected with some sort of malware. How do I know this? Because svchost is a part of the Windows operating system; it's a common system process and, because of this, some malware will try to disguise itself by using the process name "svchost". For various technical reasons I also know for a fact that Microsoft don't use {smartassembly} on it. If you want to know a little more, take a look at this Wikipedia article:

http://en.wikipedia.org/wiki/Svchost

The individual or group who wrote the malware now residing on your computer were, not surprisingly, too cheap to pay for a license for {smartassembly}, and too inept to spot that using the evaluation version would pop up this message and thus conveniently blow their cover. Hmm. why is it that criminals are besmirched with this reputation for stupidity? Oh, it's just too taxing. I might need to go for a lie down in a darkened room whilst I ruminate on this terrifying conundrum. Yes, and bring me a cup of tea, would you please?

OK, end of rant. The great news here is that it should be pretty straightforward to fix, unless you've got some really exotic brand of malware, which seems unlikely given that the criminals involved couldn't even be bothered with the most basic testing before they unleashed their creation upon the world. right, sorry, I'm really going to stop that now.

In most cases all you need to do is download and run a spyware removal tool. You should also make sure you've got some top quality, up to date antivirus software installed. For simplicity's sake, I'd just go for a big name like Norton, Symantec, or ESET NOD32, which is what we use (and it's been great). There are free and open source alternatives but, frankly, if you consider yourself a novice user, or you simply don't want to be bored with the details, just shell out for something big, well-known, and well-trusted.

Anyway, back to the spyware removal tool. I'd recommend Spybot Search and Destory (Spybot from here in), which is free, pretty easy to use, and has always served me well. I have tried others, such as AdAware, in the past, but Spybot has always seemed to do the best job of getting rid of even the most tenacious infestations.

I'm not going to give you detailed instructions on how to use Spybot to clean up your computer, partly because I'm a bit short on time right now, but mainly because the product comes with plenty of its own documentation. I will give you a quick outline of the process.

But first I'm going to give you fairly detailed instructions on how to safely download the thing because, be warned, there are hacked versions and lookalikes out there that will cheerfully infect your computer with even more (probably much nastier) malware, so you need to be sure you download and install the real thing.

So.

The only safe place to download this tool is from the Safer Networking site at:

http://www.safer-networking.org/index2.html

Do not, I repeat DO NOT, download this tool from anywhere that isn't a file hosting mirror directly linked from this site. Definitely do not even think about using bittorrent or any other p2p network to download this software. If you do download it from anywhere else, as I've already said, your computer is practically guaranteed to be infected with more (probably much nastier) malware.

Once you've gone to the Safer Networking homepage, just click on one of the links on the right for a page in your preferred language (figure 2).

Figure 2. Choose a page in the language of your choice.

Now click the Download link at the top right of the page (has an icon that looks like a 3.5 inch floppy disk above it - figure 3).

Figure 3. Here are the links at the top right of the Spybot main page.

Now, scroll down past the donation and "Important Information" sections, to the "Download" section. Now click the Download link for the latest version of Spybot, which should be the first link in the list (figure 4).

Figure 4. Click the link to download the product itself - don't worry about the detection updates, because you can get Spybot to download them itself later.

Now you need to pick a mirror using one of the "Download here" buttons on the right of the page (figure 5), but be warned: it's an unfortunate fact that most of these sites carry adverts from companies who are just about unscrupulous enough to try to trick you into downloading the wrong piece of software. It's very annoying so don't be too hasty about clicking any download links, once you're past the list of mirrors, but if you read the page content carefully you should be able to figure out which is the right link easily enough. To illustrate the problem I'm talking about, take a look at figure 6, which is a shot of the download page on the fileforum.betanews.com mirror.

Figure 5. Pick a mirror site from which to download Spybot. You can pick one of the main mirrors, or scroll down the page for other mirror sites. Whichever site you choose, from this point onwards, proceed with caution.

Figure 6. A typical download page for Spybot S&D on one of the mirror sites. Don't get me wrong, I'm not saying there's anything wrong with "Advanced Registry Optimizer" as a piece of software, and I'm definitely not going to even imply that it contains malware but, even if I were being charitable, I might use a phrase like "more than a little bit cheeky" to describe the fact that they've made their ad look like it contains a download button for the software you're really interested in. If I were to be less charitable, I might just get a little bit Bill Hicks about their marketing department. Don't be fooled.

OK, once you click this download link the file should actually start to download. I know, a bit of a voyage, right? If there'll usually be some text on the page that says something like, "Downloading spybotsd162.exe. If your download does not start soon, click here." Give it a few moments, but if it doesn't kick off automatically you can safely click that link - watch out for even more unscrupulous ads on this page though.

Now you've safely downloaded it, this is where the detailed instructions end. What you need to do next is:

• Install the software you've just downloaded by running spybotsd162.exe. You'll probably get one or more security warnings, but it's fine to continue.
• Run Spybot, either by starting it directly after installation, or via the Start menu.
• Have Spybot update itself.
• Now have it make a backup of your registry just in case something goes wrong (don't worry, it probably won't - if it does you can restore the registry backup and all should be hunky dory again).
• Get it to run a scan.
• Once it's done, you can choose the problems you want to fix - generally I just choose to fix everything.
• It'll probably need you to restart your machine to fix some of the problems. Do this. You'll be asked if you're happy for Spybot to run again on start-up.
• Restart your computer.
• Spybot will run another scan and fix any other problems you choose.
• Congratulations! Your computer should be clean.

A couple of things. Firstly, if you're in any doubt about how to use Spybot, start it up, then just read the Help until you're sure. It's not difficult to use, but it's better to be safe than sorry. Secondly, Spybot is not absolutely guaranteed to find and fix all problems, so you might want somebody who knows what they're doing to take a look at your PC anyway.

Hopefully you're now spyware free, and the {smartassembly} evaluation version message has disappeared.