what is hidden start v 2.1

Hidden start is a component of Dell DataSafe Backup Local so you must have a Dell PC preinstalled with that utility. 

There are some illustrations at Hidden Start - Run Applications and Batch Files without a Console Window or UAC Prompt [these are by the company that actually makes the Hidden start component for Dell & probably other PC makers]

The hstart.exe file [apparently in C:/Program Files/Dell DataSafe Local Backup or C:/Program Files (x86)/Dell DataSafe Local Backup] is apparently digitally signed as a Dell Component [right-click on the file & look at the Signatures tab].

Incidentally, Dell DataSafe Backup Local might seem to be completely useless but it has one unique & irreplaceable function.  You can use it to create a bootable copy of the Dell Factory Image Restore [DFIR] partition on USB or DVD-R [personally, I find USBs more reliable than DVD-Rs].  That would allow you to restore to factory condition even if your hard drive failed completely and had to be replaced*.  The function is under Dell DataSafe Backup Local, Backup, Create recovery media.  Don't even think of removing Dell DataSafe Backup Local until you have made this backup as nothing else can achieve this result for you.

* Strictly speaking, a replacement drive ought to be the same spec as the original for DFIR restoration to succeed but it seems likely that running a utility such as the*Intel® Driver Update Utility*could enable you to then manually update the drivers after which Windows Update would be happy to take over & to check them along with everything else it checks.