PCWorld highlights how old USB drives can be transformed into powerful PC rescue kits using portable applications that run without installation. Essential tools include bootable OS creators like Rufus and Ventoy, antivirus scanners like ClamWin and Stinger, and system repair utilities. These portable rescue kits enable tech support across multiple computers, offering hardware monitoring, network diagnostics, and Windows optimization capabilities. Portable apps are applications and tools that can be started directly upon clicking them, with no prior installation needed. The advantage of this is that the programs are immediately ready for use and can be started from any storage drive -- including a USB flash drive. These useful tools are then available for analyzing and maintaining any computer you slap the flash drive into, making them utterly invaluable for informal tech support duties. Let's take a look at the best portable applications for hardware analysis and system tuning, as well as a basic setup with media player, image editing, and word processing tools.