That means, that all your exe files are infected with a virus. So Backup all your Data, format the Harddisk and install Windows again.
Bevor going online the first time, you have to install the newest Servicepack avaible for your Windows Version.
You have to download it from a other clean PC, otherwise the downloaded servicepack will become infected too.
Using the offered cleaning tool for "your" virus is not a good choice IMHO, because it is not able to clean the files 100% and the chance, that the cleaner destroys the file is high!