thats a pretty common well we cant say virus, it rather more than a trojan, it has many variants which can also perform following things.

Disable task manager
Disable registry editor
Disable show hidden files
Creates a file named autorun.inf & each time u open a drive it executes,


Vanja the above procedure u told not always works, it will only enable you to view hidden files, but the new variants are too clever for that, and as soon as u enable registry settings, they disable it. The best thing is to find vbs scripts which enable registry tools, task manager, and other settings, or the best thing is to download Process Explorer, which is freely available from microsoft.com, and close the running virus execution. then download New_Folder.exe_Removal_Tool_2.5 which will help you enable all disabled settings.