Nop, you're conlcusion is incorrect. The script needs admin right if the script want to wrtie to the Policies subkey.

Solutions are:
1) LPO, GPO or POLEDIT
2) Admin script making remote registry changes, e.g.
code:
$comps=NetView2()
for each $comp in $comps
  $rc=WRITEVALUE('\\'+$comp+'\HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System','NoDispScrSavPage','1','REG_DWORD')
next
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