A method to for safely restoring files in a computing system may include: 1) identifying a backup copy of a file, 2) creating a virtualization layer on a storage device in the computing system, and 3) restoring the backup copy of the file to a virtualized location within the virtualization layer. When an application or device requests to transfer data with another application or device, a framing protocol sends one or more complete protocol data units preceded by a framing header that is aligned with the transport header. In example embodiments, images within the system, including surrogate document images are stored in tagged image file format and the TIFF header includes the surrogate document image indicator. The indicating coiled spring is made of metal, wherein the indicating coiled spring is hard to be broken and a lifetime of the indicating coiled spring is lengthened. The reference voltage is decreased as the control current increases and is varied in frequency to match the phase of the oscillator. The boosting circuit includes an amplification circuit of a cross-coupled type.