If there is any version of VSE 8.8 installed you cannot install the full package on top of that as you will get that the product is already install and it wont work. Only you can use the full package to change the version, lets say if you have VSE 8.7 and you want to upgrade to VSE 8.8 you can run VSE 8.8 full package.
When you use the full package you must use a deployment task and when you installing only a patch you must use an update task.
In this case is a "bit special" as you cannot go without patch to patch 4, so you should go to patch 2 (using an update task) and then update to patch 4 with another update task or you have another option (less secure) to uninstall the VSE 8.8 and install VSE 8.8 (full package) using a deployment task. This option is less secure as your machines will be some time (the time when you uninstall and untill you install the new version) without antivirus
I hope this answer your question.