diff --git a/src/etaoin/proc.clj b/src/etaoin/proc.clj
index c598bd76..1f5986a0 100644
--- a/src/etaoin/proc.clj
+++ b/src/etaoin/proc.clj
@@ -1,24 +1,22 @@
 (ns etaoin.proc
   (:require [clojure.java.io :as io]
-            [clojure.string :as str])
-  (:import  java.lang.IllegalThreadStateException
-            java.io.IOException))
+            [clojure.string :as str]))
 
 (def windows? (str/starts-with? (System/getProperty "os.name") "Windows"))
 
-(defn get-null-file ^java.io.File
+(defn- get-null-file ^java.io.File
   []
   (if windows?
     (io/file "NUL")
     (io/file "/dev/null")))
 
-(defn get-log-file ^java.io.File
+(defn- get-log-file ^java.io.File
   [file-path]
   (if file-path
     (io/file file-path)
     (get-null-file)))
 
-(defn java-params ^"[Ljava.lang.String;" [params]
+(defn- java-params ^"[Ljava.lang.String;" [params]
   (->> params
        (map str)
        (into-array String)))
@@ -44,27 +42,6 @@ Please ensure you have the driver installed and specify the path to it.
 For driver installation, check out the official readme file from Etaoin: %s" binary readme-link)
                   {:args args} e)))))))
 
-;; todo store those streams
-
-(defn alive? [^Process proc]
-  (.isAlive proc))
-
-(defn exit-code [^Process proc]
-  (try
-    (.exitValue proc)
-    (catch IllegalThreadStateException _)))
-
 (defn kill [^Process proc]
-  (.destroy proc))
-
-;; todo refactor those
-
-(defn read-out [^Process proc]
-  (try
-    (-> proc .getInputStream slurp)
-    (catch IOException _)))
-
-(defn read-err [^Process proc]
-  (try
-    (-> proc .getErrorStream slurp)
-    (catch IOException _)))
+  (.destroy proc)
+  (.waitFor proc))
diff --git a/test/etaoin/proc_test.clj b/test/etaoin/proc_test.clj
index 293d8980..34c2ba35 100644
--- a/test/etaoin/proc_test.clj
+++ b/test/etaoin/proc_test.clj
@@ -4,46 +4,61 @@
             [clojure.test :refer :all]
             [etaoin.proc :as proc]
             [etaoin.test-report]
+            [clojure.pprint :as pprint]
             [clojure.string :as str]))
 
 (defn get-count-chromedriver-instances
   []
   (if proc/windows?
-    (->> (sh "powershell" "-command" "(Get-Process chromedriver -ErrorAction SilentlyContinue).Path")
-         :out
-         str/split-lines
-         (remove #(str/includes? % "\\scoop\\shims\\")) ;; for the scoop users, exclude the shim process
-         (filter #(str/includes? % "chromedriver"))
-         count)
+    (let [instance-report (-> (sh "powershell" "-command" "(Get-Process chromedriver -ErrorAction SilentlyContinue).Path")
+                              :out
+                              str/split-lines)]
+      ;; more flakiness diagnosis
+      (println "windows chromedriver instance report:" instance-report)
+      (println "windows full list of running processes:")
+      ;; use Get-CimInstance, because Get-Process, does not have commandline available
+      (pprint/pprint (-> (sh "powershell" "-command" "Get-CimInstance Win32_Process | select name, commandline")
+                         :out
+                         str/split-lines))
+      (->> instance-report
+           (remove #(str/includes? % "\\scoop\\shims\\")) ;; for the scoop users, exclude the shim process
+           (filter #(str/includes? % "chromedriver"))
+           count))
     (->> (sh "sh" "-c" "ps aux")
          :out
          str/split-lines
          (filter #(str/includes? % "chromedriver"))
          count)))
 
-(deftest test-prevent-process-fork
-  (testing "certain driver port"
-    (let [port    9999
-          process (proc/run ["chromedriver" (format "--port=%d" port)])
-          _       (wait-running {:port port :host "localhost"})]
-      (is (= 1 (get-count-chromedriver-instances)))
-      (is (thrown-with-msg?
-            clojure.lang.ExceptionInfo
-            #"already in use"
-            (chrome {:port port})))
-      (proc/kill process)))
-  (testing "random driver port"
-    (let [port    9999
-          process (proc/run ["chromedriver" (format "--port=%d" port)])
-          _       (wait-running {:port port :host "localhost"})]
-      (with-chrome {:args ["--no-sandbox"]} driver
-        (is (= 2 (get-count-chromedriver-instances)))
-        (proc/kill process))))
-  (testing "connect to driver"
-    (let [port    9999
-          process (proc/run ["chromedriver" (format "--port=%d" port)])
-          _       (wait-running {:port port :host "localhost"})
-          driver  (chrome {:host "localhost" :port port :args ["--no-sandbox"]})]
-      (is (= 1 (get-count-chromedriver-instances)))
-      (quit driver)
-      (proc/kill process))))
+(deftest test-process-forking-port-specified
+  (let [port    9997
+        process (proc/run ["chromedriver" (format "--port=%d" port)])
+        _       (wait-running {:port port :host "localhost"})]
+    (is (= 1 (get-count-chromedriver-instances)))
+    (is (thrown-with-msg?
+         clojure.lang.ExceptionInfo
+         #"already in use"
+         (chrome {:port port})))
+    (proc/kill process)))
+
+(deftest test-process-forking-port-random
+  (let [port    9998
+        process (proc/run ["chromedriver" (format "--port=%d" port)])
+        _       (wait-running {:port port :host "localhost"})]
+    (with-chrome {:args ["--no-sandbox"]} driver
+        ;; added to diagnose flakyness on windows on CI
+      (println "automatically chosen port->" (:port driver))
+        ;; added to diagnose flakyness on windows on CI
+      (wait-running driver)
+      (is (= 2 (get-count-chromedriver-instances))))
+    (proc/kill process)))
+
+(deftest test-process-forking-connect-existing
+  (let [port    9999
+        process (proc/run ["chromedriver" (format "--port=%d" port)])
+        _       (wait-running {:port port :host "localhost"})
+        driver  (chrome {:host "localhost" :port port :args ["--no-sandbox"]})]
+    (wait-running driver)
+    (is (= 1 (get-count-chromedriver-instances)))
+    (quit driver)
+    (proc/kill process)))