diff --git a/win/NSIS.template.in b/win/NSIS.template.in
index c31488c44..8b6b142ea 100644
--- a/win/NSIS.template.in
+++ b/win/NSIS.template.in
@@ -470,21 +470,21 @@ FunctionEnd
 !insertmacro StrStr "un."
 
 Function Trim ; Added by Pelaca
-  Exch $R1
-  Push $R2
+	Exch $R1
+	Push $R2
 Loop:
-  StrCpy $R2 "$R1" 1 -1
-  StrCmp "$R2" " " RTrim
-  StrCmp "$R2" "$\n" RTrim
-  StrCmp "$R2" "$\r" RTrim
-  StrCmp "$R2" ";" RTrim
-  GoTo Done
+	StrCpy $R2 "$R1" 1 -1
+	StrCmp "$R2" " " RTrim
+	StrCmp "$R2" "$\n" RTrim
+	StrCmp "$R2" "$\r" RTrim
+	StrCmp "$R2" ";" RTrim
+	GoTo Done
 RTrim:
-  StrCpy $R1 "$R1" -1
-  Goto Loop
+	StrCpy $R1 "$R1" -1
+	Goto Loop
 Done:
-  Pop $R2
-  Exch $R1
+	Pop $R2
+	Exch $R1
 FunctionEnd
 
 Function ConditionalAddToRegistry
@@ -937,11 +937,20 @@ Function .onInit
 ;Run the uninstaller
 uninst:
   ClearErrors
-  StrCpy $2 $0 1
-  StrCmp '"' $2 0 +3 ; checks if string is quoted (CPack before v3.20.6 did not quote it)
-  ExecWait '$0 /S'
-  Goto +2
-  ExecWait '"$0" /S'
+  # $0 should _always_ be quoted, however older versions of CMake did not
+  # do this.  We'll conditionally remove the begin/end quotes.
+  # Remove first char if quote
+  StrCpy $2 $0 1 0      # copy first char
+  StrCmp $2 "$\"" 0 +2  # if char is quote
+  StrCpy $0 $0 "" 1     # remove first char
+  # Remove last char if quote
+  StrCpy $2 $0 1 -1     # copy last char
+  StrCmp $2 "$\"" 0 +2  # if char is quote
+  StrCpy $0 $0 -1       # remove last char
+
+  StrLen $2 "\@CPACK_NSIS_UNINSTALL_NAME@.exe"
+  StrCpy $3 $0 -$2 # remove "\@CPACK_NSIS_UNINSTALL_NAME@.exe" from UninstallString to get path
+  ExecWait '"$0" /S _?=$3' ;Do not copy the uninstaller to a temp file
 
   IfErrors uninst_failed inst
 uninst_failed:
@@ -978,7 +987,7 @@ inst:
     ;MessageBox MB_OK 'User "$0" is in the Admin group'
     StrCpy $SV_ALLUSERS "AllUsers"
     Goto done
-  StrCmp $1 "Power" 0 +4
+  StrCmp $1 "Power" 0 +3
     SetShellVarContext all
     ;MessageBox MB_OK 'User "$0" is in the Power Users group'
     StrCpy $SV_ALLUSERS "AllUsers"