diff --git a/src/internal/syscall/windows/security_windows.go b/src/internal/syscall/windows/security_windows.go
index e528744caa..aed04c61c4 100644
--- a/src/internal/syscall/windows/security_windows.go
+++ b/src/internal/syscall/windows/security_windows.go
@@ -175,3 +175,38 @@ func GetUserName(format uint32) (string, error) {
 		}
 	}
 }
+
+// getTokenInfo retrieves a specified type of information about an access token.
+func getTokenInfo(t syscall.Token, class uint32, initSize int) (unsafe.Pointer, error) {
+	n := uint32(initSize)
+	for {
+		b := make([]byte, n)
+		e := syscall.GetTokenInformation(t, class, &b[0], uint32(len(b)), &n)
+		if e == nil {
+			return unsafe.Pointer(&b[0]), nil
+		}
+		if e != syscall.ERROR_INSUFFICIENT_BUFFER {
+			return nil, e
+		}
+		if n <= uint32(len(b)) {
+			return nil, e
+		}
+	}
+}
+
+type TOKEN_GROUPS struct {
+	GroupCount uint32
+	Groups     [1]SID_AND_ATTRIBUTES
+}
+
+func (g *TOKEN_GROUPS) AllGroups() []SID_AND_ATTRIBUTES {
+	return (*[(1 << 28) - 1]SID_AND_ATTRIBUTES)(unsafe.Pointer(&g.Groups[0]))[:g.GroupCount:g.GroupCount]
+}
+
+func GetTokenGroups(t syscall.Token) (*TOKEN_GROUPS, error) {
+	i, e := getTokenInfo(t, syscall.TokenGroups, 50)
+	if e != nil {
+		return nil, e
+	}
+	return (*TOKEN_GROUPS)(i), nil
+}
diff --git a/src/os/user/lookup_windows.go b/src/os/user/lookup_windows.go
index 804fc64cc1..5d99060065 100644
--- a/src/os/user/lookup_windows.go
+++ b/src/os/user/lookup_windows.go
@@ -434,17 +434,45 @@ func lookupGroupId(gid string) (*Group, error) {
 }
 
 func listGroups(user *User) ([]string, error) {
-	sid, err := syscall.StringToSid(user.Uid)
-	if err != nil {
-		return nil, err
-	}
-	username, domain, err := lookupUsernameAndDomain(sid)
-	if err != nil {
-		return nil, err
-	}
-	sids, err := listGroupsForUsernameAndDomain(username, domain)
-	if err != nil {
-		return nil, err
+	var sids []string
+	if u, err := Current(); err == nil && u.Uid == user.Uid {
+		// It is faster and more reliable to get the groups
+		// of the current user from the current process token.
+		err := runAsProcessOwner(func() error {
+			t, err := syscall.OpenCurrentProcessToken()
+			if err != nil {
+				return err
+			}
+			defer t.Close()
+			groups, err := windows.GetTokenGroups(t)
+			if err != nil {
+				return err
+			}
+			for _, g := range groups.AllGroups() {
+				sid, err := g.Sid.String()
+				if err != nil {
+					return err
+				}
+				sids = append(sids, sid)
+			}
+			return nil
+		})
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		sid, err := syscall.StringToSid(user.Uid)
+		if err != nil {
+			return nil, err
+		}
+		username, domain, err := lookupUsernameAndDomain(sid)
+		if err != nil {
+			return nil, err
+		}
+		sids, err = listGroupsForUsernameAndDomain(username, domain)
+		if err != nil {
+			return nil, err
+		}
 	}
 	// Add the primary group of the user to the list if it is not already there.
 	// This is done only to comply with the POSIX concept of a primary group.