Many malware and virus experts report that the latest version of the Conflicker worm will go into action and could cause major problems on April 1st. Version A of Conflicker reportedly used 250 domain names a day, while this new self-updating "C" version of the worm could possibly use up to 50,000.
While there is not a definite answer as to what Conflicker can do, users who get infected may be unable to install Windows security patches, leaving them vulnerable to spam, keylogging, even ID theft. The worm tries to spread itself through shared network folders, so if you use multiple machines on a home network, all your computers could be compromised.
You can download the most recent Microsoft security patches at windowsupdate.microsoft.com.
To see whether or not you're infected you can run a free scan at Windows Live OneCare.
Make sure you're anti-virus software is up to date. If you don't have an anti-virus program, I recommend Avast!, which you can download for free at www.avast.com.