how to uninstall the software in dos mode?

Clarifications

DOS doesn't care one little bit about software that is 'installed'. You can delete files and folders in 'DOS mode' (aka at the command prompt) till you're blue in the face. But, uninstall needs to be run through Windows to remove entries in the registry. And, if you delete the files before you've run the uninstaller, it will often fail because it can't find the files that it needs to delete. Or, worse yet, you've deleted the uninstaller itself.