Documentation - Log
This page in the program show the progress of the modification. If it's grayed out then you must push the Apply button for it to be enabled and start processing.
If it takes too long during component removal try disabling the antivirus protection or set it to scan only executed files.
You may notice this problem by seeing in the Task Manager that the System process is taking a lot of CPU time and vLite stays idle. It is nothing strange, simply the antivirus is scanning the majority of files from the image, and Vista has a lot of files.