"Due to virus my old files are gone. My desktop is still missing the old icons and the old background". How to fix the problem?

The above-mentioned problem is caused by the viruses known as fake system optimizers and defragmenters, such as Windows Fix Disk, Windows Repair, Windows Restore, Windows Recovery and several other malware programs. We have been receiving plenty of e-mail over the latest period of time with similar questions as described below.