First of all, I am fairly sure that I saw the solution to this here, but for the life of me, and I’ve looked for at least a year, I cannot re-find the answer.
Basically, someone had posted a small batch file script that would self elevate from administrator to system without any complaints, and I miss this very much!!!! I had it for a long time but on re-doing OS I lost it!
The important part of this is NOT using ANY third party or not built in functionality!
Source: Windows Questions