diff -rN -u old-tahoe/src/allmydata/control.py new-tahoe/src/allmydata/control.py
--- old-tahoe/src/allmydata/control.py	2009-12-20 15:58:04 +0000
+++ new-tahoe/src/allmydata/control.py	2009-12-20 15:58:05 +0000
@@ -10,24 +10,39 @@
 from allmydata.immutable import upload
 from twisted.python import log
 
+try:
+    import win32process
+except:
+    win32process = None
+
 def get_memory_usage():
-    # this is obviously linux-specific
-    stat_names = ("VmPeak",
-                  "VmSize",
-                  #"VmHWM",
-                  "VmData")
     stats = {}
-    try:
-        for line in open("/proc/self/status", "r").readlines():
-            name, right = line.split(":",2)
-            if name in stat_names:
-                assert right.endswith(" kB\n")
-                right = right[:-4]
-                stats[name] = int(right) * 1024
-    except:
-        # Probably not on (a compatible version of) Linux
-        stats['VmSize'] = 0
-        stats['VmPeak'] = 0
+    stats['VmSize'] = 0
+    stats['VmPeak'] = 0
+    stats['VmData'] = 0
+    if win32process:
+        # Windows-specific
+        process_memory_counters = win32process.GetProcessMemoryInfo(win32process.GetCurrentProcess())
+        stats['VmSize'] = process_memory_counters['WorkingSetSize']
+        stats['VmPeak'] = process_memory_counters['PeakWorkingSetSize']
+        stats['VmData'] = stats['VmSize']
+    else:
+        # this is obviously linux-specific
+        stat_names = ("VmPeak",
+                      "VmSize",
+                      #"VmHWM",
+                      "VmData")
+        try:
+            for line in open("/proc/self/status", "r").readlines():
+                name, right = line.split(":",2)
+                if name in stat_names:
+                    assert right.endswith(" kB\n")
+                    right = right[:-4]
+                    stats[name] = int(right) * 1024
+        except:
+            # Probably not on (a compatible version of) Linux
+            pass
+
     return stats
 
 def log_memory_usage(where=""):
diff -rN -u old-tahoe/src/allmydata/test/check_memory.py new-tahoe/src/allmydata/test/check_memory.py
--- old-tahoe/src/allmydata/test/check_memory.py	2009-12-20 15:58:05 +0000
+++ new-tahoe/src/allmydata/test/check_memory.py	2009-12-20 15:58:05 +0000
@@ -8,7 +8,7 @@
 from allmydata import client, introducer
 from allmydata.immutable import upload
 from allmydata.scripts import create_node
-from allmydata.util import fileutil, pollmixin
+from allmydata.util import fileutil, pollmixin, find_exe
 from foolscap.api import Tub, fireEventually, flushEventualQueue
 from twisted.python import log
 
@@ -263,7 +263,41 @@
         pp = ClientWatcher()
         self.proc_done = pp.d = defer.Deferred()
         logfile = os.path.join(self.basedir, "client.log")
-        cmd = ["twistd", "-n", "-y", "tahoe-client.tac", "-l", logfile]
+        # code imported from do_start() of src/allmydata/scripts/startstop_node.py
+        cmd = find_exe.find_exe('twistd')
+        if not cmd:
+            # If 'twistd' wasn't on $PATH, maybe we're running from source and
+            # Twisted was built as one of our dependencies. If so, we're at
+            # BASEDIR/src/allmydata/test/check_memory.py, and it's at
+            # BASEDIR/support/$BINDIR/twistd
+            up = os.path.dirname
+            TAHOEDIR = up(up(up(up(os.path.abspath(__file__)))))
+            if sys.platform == "win32":
+                bin_dir = "Scripts"
+            else:
+                bin_dir = "bin"
+            bindir = os.path.join(TAHOEDIR, "support", bin_dir)
+
+            maybe = os.path.join(bindir, "twistd")
+            if os.path.exists(maybe):
+                cmd = [maybe]
+                oldpath = os.environ.get("PATH", "").split(os.pathsep)
+                os.environ["PATH"] = os.pathsep.join(oldpath + [bindir])
+                # sys.path and $PYTHONPATH are taken care of by the extra code in
+                # 'setup.py trial'
+            else:
+                maybe = maybe+'.py'
+                if os.path.exists(maybe):
+                    cmd = [sys.executable, maybe]
+                    oldpath = os.environ.get("PATH", "").split(os.pathsep)
+                    os.environ["PATH"] = os.pathsep.join(oldpath + [bindir])
+                    # sys.path and $PYTHONPATH are taken care of by the extra code in
+                    # 'setup.py trial'
+        if not cmd:
+            raise TwistdNotFoundError("Can't find twistd (it comes with Twisted)")
+        # End of code import from do_start() of src/allmydata/scripts/startstop_node.py
+
+        cmd.extend(["-n", "-y", "tahoe-client.tac", "-l", logfile])
         env = os.environ.copy()
         self.proc = reactor.spawnProcess(pp, cmd[0], cmd, env, path=clientdir)
         log.msg("CLIENT STARTED")