Panda USB Vaccine is a free utility from Panda Security Research which helps prevent malware infections due to the autorun feature of Windows Operating Systems. Once executed the user can choose two types of vaccinations: Computer Vaccination or USB Drive Vaccination.

USB Vaccine allows users to vaccinate their PCs in order to disable autorun completely so that no program from any USB/CD/DVD drive (regardless of whether they have been previously vaccinated or not) can auto-execute. This is a really helpful feature as there is no user friendly and easy way of completely disabling autorun on a Windows PC.

Panda USB Vaccine can be used on individual USB drives to disable its autorun.inf file in order to prevent malware infections from spreading automatically. When applied on a USB drive, the vaccine permanently blocks an innocuous AUTORUN.INF file, preventing it from being read, created, deleted or modified. Once applied it effectivelly disables Windows from automatically executing any malicious file that might be stored in that particular USB drive. The drive can otherwise be used normally and files (even malware) copied to/from it, but they will be prevented from opening automatically. Panda USB Vaccine currently only works on FAT & FAT32 USB drives. Also keep in mind that USB drives that have been vaccinated cannot be reversed except with a format.