You will need to be more aggressive with applications of this type. Since you cannot delete the files because they are in use or locked by the kernel, the removal process involves using 3rd party tools that have the ability to detach the executable from the kernel memory. I would like to recommend you LockHunter for this particular operation. Download ind install the application then navigate to the installation folder of Deal Vault and right click it and select What is locking this file?. If the files/folders are locked you can detach them and use Delete. Once you delete these files (a computer restart might be necessary), Deal Vault will not be able to start anymore. You can also clean the Startup using the Startup tab from the configuration utility (Start > Run > msconfig).