I have an infuriating problem with my Dell Vostro 1720 laptop ever since upgrading from Vista Pro to 7 Pro. Randomly, without any interaction from me, application dlls just go missing. I can install an application one day, and the next, when I try to launch it, I will be prompted with "XXXYYY.dll is missing" The PC is virus and spyware free and I've applied all Windows updates. I tried a full repair install of Windows 7 Pro using the CD and the "Upgrade" option, and whilst this did fix the problem temporarily, withing a couple of weeks, the problem was back! Has anyone else come across this, and can anyone offer any advice? As you can imagine, it is a right pain in the backside!!