It seems that the number of "healthy" computers in Bhutan can be counted on a single hand. Many computers that I'm running into show clear symptoms of a sick machine, some of them so terminally ill that the only cure is the IT equivalent of a brain transplant, i.e., re-formating the hard disk. Most computer viruses spread when you insert an infected USB drive (also known as pen drive) into your computer. Once infected, your computer starts to slow down or otherwise behave strangely. If you have good and up-to-date anti-virus software installed, this can sometimes protect your computer.
In addition to slowing down your computer and otherwise being a major nuisance, malware (MALicious softWARE, such as viruses, torjan horses, and more) can also use your Internet connection. For example, Trojan horses can steal your files and passwords and send them over the Internet back to the hackers. Rootkits - another type of malware - often use your computer to attack other computers. All this takes place while you're online, and most likely you won't even notice it - although you might be annoyed by the apparently long time it takes for your Facebook wall to load.
Given Bhutan Telecom's consumer broadband prices - about Nu 160 per 1GB - a virus that uses a mere 0.5kB/second will cost you about Nu. 200 a month, assuming the infected computer is connected to the Internet 24 hours a day. If you have several infected computers sharing your Internet connection, your bill will be even higher. My advice: Obviously, always try to keep your computer clean. However, If you suspect a computer infection, turn off the broadband modem or computer(s) when not in use.
And on a national level: Given the increasing number of Internet-connected computers, the poor "health" of so many of them, and the finite international bandwidth, what price - in productivity and otherwise - are we paying for all those bandwidth-gulping computer viruses?