If you don't have a resident anti-virus program, the first step should be her choice, downloading and installing. Not necessarily very long and carefully select all the parameters of anti - virus- for reviewing almost any of them, even paid, can be set free for a period from two weeks to one month. In any case, this period you will be quite enough to check all the disks his computer. For example, you can download and install Avira antivirus, although there are also Nod 32, Kaspersky, Panda, Dr Web and others.
After installing the antivirus asks to restart the computer - do it. Then open Windows Explorer. This can be done by pressing shortcut keys WIN + E (Russian) or double click the icon "My computer".
Hover the mouse over the icon diskand you had to check, and click the right-mouse button. In the popup context menu, click check it for viruses. Depending on the type you have installed antivirus, the wording of this item may vary - in the case of Avira the inscription would be: "scan selected files with AntiVir". Antivirus will check the diskand if the suspicious files are detected, it will prompt you to select the options with them.
You can do without Windows Explorer, open the antivirus by double-clicking its icon in the system tray of your desktop. The anti-virus window, locate the option of checking local disks. From Avira to do this in the left pane to expand the section "Local protection", then in the right pane, click the bottom option ("custom scan"). The result will reveal a list of disks to your PC with checkboxes next to each of them – check the check boxes for. Then click on any of them, right-click and select the context menu item "Run test" or just press the hotkey F3.