diff --git a/docs/implementation-plan.v1.md b/docs/implementation-plan.v1.md
index 714189e..9cf621a 100644
--- a/docs/implementation-plan.v1.md
+++ b/docs/implementation-plan.v1.md
@@ -837,8 +837,11 @@ in a mode-0600 host-side password file, and preserve the normal Windows 10
 The harness verifies that token and fails closed if policy filters it; do not
 globally disable UAC or use a bypass. `test-host install` uses that identity
 only to execute the staged real `rvbox.exe --install-service` path and proves it
-by polling SCM. It is not an RVBox product process, a service/broker, or a Task
-Scheduler dependency, and it never enters the daemon's command-context choice.
+by polling SCM. It then requires that the provisioning identity is absent from
+`query user`; otherwise reset before any active-session command test, because a
+second logon could contaminate WTS candidate selection. It is not an RVBox
+product process, a service/broker, or a Task Scheduler dependency, and it never
+enters the daemon's command-context choice.
 The normal active `rvboxtest` session remains the target for execution-role
 tests. The consent-prompt branch itself remains an interactive UAC test; an
 invisible Guest Control session must never answer it.
diff --git a/docs/testing-vm.md b/docs/testing-vm.md
index d723845..1f99b4d 100644
--- a/docs/testing-vm.md
+++ b/docs/testing-vm.md
@@ -187,8 +187,12 @@ remain mode `0600` on Helium and neither value is recorded in run
 reports or artifacts. `test-host install` first verifies that the reset guest
 has no `RVBoxClient`, checks the provisioner's High Mandatory Level, invokes
 the actual staged `rvbox.exe --install-service --config ...`, and polls SCM for
-`RUNNING`. `run` may then exercise reconfigure/start/restart paths. Snapshot
-reset removes the installed service and all RVBox data again.
+`RUNNING`. It then checks that the provisioning account is no longer present in
+`query user`. A lingering Administrator session could become a second WTS
+candidate and contaminate `ACTIVE_USER` / `ACTIVE_USER_ELEVATED` tests, so the
+harness fails before command dispatch and the run must reset. `run` may then
+exercise reconfigure/start/restart paths. Snapshot reset removes the installed
+service and all RVBox data again.
 
 The provisioner is fixture administration only: it is not shipped with RVBox,
 not a product service/broker, not a Task Scheduler dependency, and never
diff --git a/scripts/windows/test-host b/scripts/windows/test-host
index f2eb42f..0904c1b 100755
--- a/scripts/windows/test-host
+++ b/scripts/windows/test-host
@@ -250,6 +250,15 @@ assert_staged_guest() {
         fail "staged guest bundle is missing rvbox.exe or client.toml"
 }
 
+assert_provisioner_absent() {
+    # A second logged-on Administrator could become an additional WTS active
+    # candidate and invalidate ACTIVE_* selection tests.  Do not guess which
+    # account the supervisor would choose: fail before dispatch and reset.
+    guest_run --exe 'C:\Windows\System32\cmd.exe' --wait-stdout --wait-stderr --unquoted-args -- \
+        /d /s /c "query user | findstr /i /c:\"$provisioner_user\" >NUL & if errorlevel 1 echo RVBOX_GUEST_OK" >/dev/null || \
+        fail "fixture provisioner remains logged on; reset before active-session tests"
+}
+
 wait_guest_additions() {
     attempt=0
     while [ "$attempt" -lt 60 ]; do
@@ -357,6 +366,7 @@ case "$action" in
             run --exe "$guest_root\\rvbox.exe" --unquoted-args -- \
             --install-service --config "$guest_root\\client.toml" </dev/null >/dev/null 2>&1 || true
         wait_service RUNNING
+        assert_provisioner_absent
         step install-scm-service-running
         printf 'service=RVBoxClient state=RUNNING install=clean-baseline\n'
         ;;