Fred Spring asks: when I install certain games my antivirus software tells me it has detected malware. It looks like the game has been installed but when I come to run it, it doesn't work. Can you explain what is going on and whether I should be concerned about this malware?
Very occasionally, antivirus products will produce a 'false positive' result. This happens where the pattern they have chosen as a kind of fingerprint for a given virus matches with a pattern in harmless program files.
The first thing to consider is: did you obtain the game from a trustworthy source? If you downloaded it over a peer-to-peer file-sharing network, then the answer must be no. P2P networks are notorious avenues for spreading malware.
I suggest that you get a second opinion on the 'virus'. Have it tested by the latest up-to-date versions of all of the main AV products. This can be done in one easy step. Go to the site www.virustotal.com for a free scanning service.
Hit the Browse button and select the file that your antivirus program detects as viral. After a few minutes you will be presented with a table of the results found by all the other AV scanners.