diff --git a/cmds/portmaster-core/main.go b/cmds/portmaster-core/main.go
index 630f5827..01d71402 100644
--- a/cmds/portmaster-core/main.go
+++ b/cmds/portmaster-core/main.go
@@ -55,7 +55,10 @@ func initialize() *service.Instance {
 
 	// Create instance.
 	var execCmdLine bool
-	instance, err := service.New(&service.ServiceConfig{})
+	instance, err := service.New(&service.ServiceConfig{
+		IsRunningAsService:    isRunningAsService(),
+		DefaultRestartCommand: defaultRestartCommand,
+	})
 	switch {
 	case err == nil:
 		// Continue
diff --git a/cmds/portmaster-core/main_linux.go b/cmds/portmaster-core/main_linux.go
index aa8d9a60..e8268dd7 100644
--- a/cmds/portmaster-core/main_linux.go
+++ b/cmds/portmaster-core/main_linux.go
@@ -4,14 +4,19 @@ import (
 	"fmt"
 	"log/slog"
 	"os"
+	"os/exec"
 	"os/signal"
 	"syscall"
 	"time"
 
+	processInfo "github.com/shirou/gopsutil/process"
+
 	"github.com/safing/portmaster/base/log"
 	"github.com/safing/portmaster/service"
 )
 
+var defaultRestartCommand = exec.Command("systemctl", "restart", "portmaster")
+
 func run(instance *service.Instance) {
 	// Set default log level.
 	log.SetLogLevel(log.WarningLevel)
@@ -98,3 +103,20 @@ func run(instance *service.Instance) {
 
 	os.Exit(instance.ExitCode())
 }
+
+func isRunningAsService() bool {
+	// Get the current process ID
+	pid := os.Getpid()
+
+	currentProcess, err := processInfo.NewProcess(int32(pid))
+	if err != nil {
+		return false
+	}
+
+	ppid, err := currentProcess.Ppid()
+	if err != nil {
+		return false
+	}
+	// Check if the parent process ID is 1 == init system
+	return ppid == 1
+}
diff --git a/cmds/portmaster-core/main_windows.go b/cmds/portmaster-core/main_windows.go
index 9b3798c3..cf47760e 100644
--- a/cmds/portmaster-core/main_windows.go
+++ b/cmds/portmaster-core/main_windows.go
@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"log/slog"
 	"os"
+	"os/exec"
 	"os/signal"
 	"sync"
 	"syscall"
@@ -24,6 +25,8 @@ var (
 	// wait groups
 	runWg    sync.WaitGroup
 	finishWg sync.WaitGroup
+
+	defaultRestartCommand = exec.Command("sc.exe", "restart", "PortmasterCore")
 )
 
 const serviceName = "PortmasterCore"
@@ -168,3 +171,11 @@ func registerSignalHandler(instance *service.Instance) {
 		}
 	}()
 }
+
+func isRunningAsService() bool {
+	isService, err := svc.IsWindowsService()
+	if err != nil {
+		return false
+	}
+	return isService
+}
diff --git a/service/config.go b/service/config.go
index 85a98603..8823ba5a 100644
--- a/service/config.go
+++ b/service/config.go
@@ -1,3 +1,8 @@
 package service
 
-type ServiceConfig struct{}
+import "os/exec"
+
+type ServiceConfig struct {
+	IsRunningAsService    bool
+	DefaultRestartCommand *exec.Cmd
+}
diff --git a/service/core/api.go b/service/core/api.go
index 2c465ccc..bb63464b 100644
--- a/service/core/api.go
+++ b/service/core/api.go
@@ -19,7 +19,6 @@ import (
 	"github.com/safing/portmaster/service/process"
 	"github.com/safing/portmaster/service/resolver"
 	"github.com/safing/portmaster/service/status"
-	"github.com/safing/portmaster/service/updates"
 	"github.com/safing/portmaster/spn/captain"
 )
 
@@ -149,8 +148,8 @@ func shutdown(_ *api.Request) (msg string, err error) {
 func restart(_ *api.Request) (msg string, err error) {
 	log.Info("core: user requested restart via action")
 
-	// Let the updates module handle restarting.
-	updates.RestartNow()
+	// Trigger restart
+	module.instance.Restart()
 
 	return "restart initiated", nil
 }
diff --git a/service/core/core.go b/service/core/core.go
index 60ad5857..1f41285c 100644
--- a/service/core/core.go
+++ b/service/core/core.go
@@ -114,6 +114,7 @@ func New(instance instance) (*Core, error) {
 
 type instance interface {
 	Shutdown()
+	Restart()
 	AddWorkerInfoToDebugInfo(di *debug.Info)
 	BinaryUpdates() *updates.Updates
 	IntelUpdates() *updates.Updates
diff --git a/service/instance.go b/service/instance.go
index 4c522a34..7887b0ef 100644
--- a/service/instance.go
+++ b/service/instance.go
@@ -4,14 +4,17 @@ import (
 	"context"
 	"fmt"
 	"os"
+	"os/exec"
 	"path/filepath"
 	go_runtime "runtime"
+	"strings"
 	"sync/atomic"
 	"time"
 
 	"github.com/safing/portmaster/base/api"
 	"github.com/safing/portmaster/base/config"
 	"github.com/safing/portmaster/base/database/dbmodule"
+	"github.com/safing/portmaster/base/log"
 	"github.com/safing/portmaster/base/metrics"
 	"github.com/safing/portmaster/base/notifications"
 	"github.com/safing/portmaster/base/rng"
@@ -101,7 +104,9 @@ type Instance struct {
 	sluice    *sluice.SluiceModule
 	terminal  *terminal.TerminalModule
 
-	CommandLineOperation func() error
+	CommandLineOperation  func() error
+	isRunningAsService    bool
+	defaultRestartCommand *exec.Cmd
 }
 
 func getCurrentBinaryFolder() (string, error) {
@@ -178,6 +183,8 @@ func New(svcCfg *ServiceConfig) (*Instance, error) { //nolint:maintidx
 	// Create instance to pass it to modules.
 	instance := &Instance{}
 	instance.ctx, instance.cancelCtx = context.WithCancel(context.Background())
+	instance.isRunningAsService = svcCfg.IsRunningAsService
+	instance.defaultRestartCommand = svcCfg.DefaultRestartCommand
 
 	var err error
 
@@ -671,7 +678,7 @@ func (i *Instance) Restart() {
 	i.core.EventRestart.Submit(struct{}{})
 	time.Sleep(10 * time.Millisecond)
 
-	i.shutdown(RestartExitCode)
+	i.serviceRestart()
 }
 
 // Shutdown asynchronously stops the instance.
@@ -700,6 +707,25 @@ func (i *Instance) shutdown(exitCode int) {
 	})
 }
 
+func (i *Instance) serviceRestart() {
+	if !i.isRunningAsService {
+		i.shutdown(RestartExitCode)
+		return
+	}
+	cmd := i.defaultRestartCommand
+
+	// Check if user defined custom command for restarting the service.
+	restartCommand, exists := os.LookupEnv("PORTMASTER_RESTART_COMMAND")
+
+	log.Debugf(`instance: running command "%s", %v`, restartCommand, exists)
+	if exists && restartCommand != "" {
+		commandSplit := strings.Split(restartCommand, " ")
+		cmd = exec.Command(commandSplit[0], commandSplit[1:]...)
+	}
+	log.Debugf("instance: running command %s", cmd.String())
+	_ = cmd.Run()
+}
+
 // Stopping returns whether the instance is shutting down.
 func (i *Instance) Stopping() bool {
 	return i.ctx.Err() != nil
diff --git a/service/updates/downloader.go b/service/updates/downloader.go
index 3cc35624..e5d1d54d 100644
--- a/service/updates/downloader.go
+++ b/service/updates/downloader.go
@@ -16,6 +16,7 @@ import (
 	"strings"
 
 	semver "github.com/hashicorp/go-version"
+
 	"github.com/safing/portmaster/base/log"
 )
 
diff --git a/service/updates/index.go b/service/updates/index.go
deleted file mode 100644
index de15a98b..00000000
--- a/service/updates/index.go
+++ /dev/null
@@ -1 +0,0 @@
-package updates
diff --git a/service/updates/main.go b/service/updates/main.go
deleted file mode 100644
index de15a98b..00000000
--- a/service/updates/main.go
+++ /dev/null
@@ -1 +0,0 @@
-package updates
diff --git a/service/updates/module.go b/service/updates/module.go
index 625fe395..cd29c3f7 100644
--- a/service/updates/module.go
+++ b/service/updates/module.go
@@ -150,7 +150,7 @@ func (u *Updates) applyUpdates(_ *mgr.WorkerCtx) error {
 		// Perform restart.
 		u.instance.Restart()
 	} else {
-		// Update completed and no restart was needed. Submit an event.
+		// Update completed and no restart is needed. Submit an event.
 		u.EventResourcesUpdated.Submit(struct{}{})
 	}
 	return nil
diff --git a/service/updates/registry.go b/service/updates/registry.go
index 4a797947..8ffc461f 100644
--- a/service/updates/registry.go
+++ b/service/updates/registry.go
@@ -8,6 +8,7 @@ import (
 	"path/filepath"
 
 	semver "github.com/hashicorp/go-version"
+
 	"github.com/safing/portmaster/base/log"
 )
 
diff --git a/service/updates/restart.go b/service/updates/restart.go
deleted file mode 100644
index 66ee82d8..00000000
--- a/service/updates/restart.go
+++ /dev/null
@@ -1,85 +0,0 @@
-package updates
-
-import (
-	"sync"
-	"time"
-
-	"github.com/tevino/abool"
-
-	"github.com/safing/portmaster/base/log"
-)
-
-var (
-	// RebootOnRestart defines whether the whole system, not just the service,
-	// should be restarted automatically when triggering a restart internally.
-	RebootOnRestart bool
-
-	restartPending   = abool.New()
-	restartTriggered = abool.New()
-
-	restartTime     time.Time
-	restartTimeLock sync.Mutex
-)
-
-// IsRestarting returns whether a restart has been triggered.
-func IsRestarting() bool {
-	return restartTriggered.IsSet()
-}
-
-// RestartIsPending returns whether a restart is pending.
-func RestartIsPending() (pending bool, restartAt time.Time) {
-	if restartPending.IsNotSet() {
-		return false, time.Time{}
-	}
-
-	restartTimeLock.Lock()
-	defer restartTimeLock.Unlock()
-
-	return true, restartTime
-}
-
-// DelayedRestart triggers a restart of the application by shutting down the
-// module system gracefully and returning with RestartExitCode. The restart
-// may be further delayed by up to 10 minutes by the internal task scheduling
-// system. This only works if the process is managed by portmaster-start.
-func DelayedRestart(delay time.Duration) {
-	// Check if restart is already pending.
-	if !restartPending.SetToIf(false, true) {
-		return
-	}
-
-	// Schedule the restart task.
-	log.Warningf("updates: restart triggered, will execute in %s", delay)
-	restartAt := time.Now().Add(delay)
-	// module.restartWorkerMgr.Delay(delay)
-
-	// Set restartTime.
-	restartTimeLock.Lock()
-	defer restartTimeLock.Unlock()
-	restartTime = restartAt
-}
-
-// AbortRestart aborts a (delayed) restart.
-func AbortRestart() {
-	if restartPending.SetToIf(true, false) {
-		log.Warningf("updates: restart aborted")
-
-		// Cancel schedule.
-		// module.restartWorkerMgr.Delay(0)
-	}
-}
-
-// TriggerRestartIfPending triggers an automatic restart, if one is pending.
-// This can be used to prepone a scheduled restart if the conditions are preferable.
-func TriggerRestartIfPending() {
-	// if restartPending.IsSet() {
-	// 	module.restartWorkerMgr.Go()
-	// }
-}
-
-// RestartNow immediately executes a restart.
-// This only works if the process is managed by portmaster-start.
-func RestartNow() {
-	restartPending.Set()
-	// module.restartWorkerMgr.Go()
-}
diff --git a/spn/captain/hooks.go b/spn/captain/hooks.go
index d21bd67b..6e1b1010 100644
--- a/spn/captain/hooks.go
+++ b/spn/captain/hooks.go
@@ -1,7 +1,6 @@
 package captain
 
 import (
-	"github.com/safing/portmaster/service/updates"
 	"github.com/safing/portmaster/spn/conf"
 	"github.com/safing/portmaster/spn/docks"
 )
@@ -41,5 +40,7 @@ func updateConnectionStatus() {
 			return
 		}
 	}
-	updates.TriggerRestartIfPending()
+
+	// TODO(vladimir): what was this needed for?
+	// updates.TriggerRestartIfPending()
 }
diff --git a/spn/captain/intel.go b/spn/captain/intel.go
index 68b7a74d..ac1145a6 100644
--- a/spn/captain/intel.go
+++ b/spn/captain/intel.go
@@ -44,7 +44,7 @@ func updateSPNIntel(_ context.Context, _ interface{}) (err error) {
 
 	// Check if there is something to do.
 	// TODO(vladimir): is update check needed
-	if intelResource != nil { //&& !intelResource.UpgradeAvailable() {
+	if intelResource != nil { // && !intelResource.UpgradeAvailable() {
 		return nil
 	}