My laptop hangs at "Windows is shutting down" sometimes. When I turn my machine off, I don't ever know if it

When I turn off my machine, I don't ever know what gonna happen. Sometimes it's just gonna turn itself off, but sometimes it doesn't.

when I start the machine again, there's no error. Is that a good sign?

Is there a way to fix that?
Is it harmful?

I did ctr+alt+del, and there are not that many processes running. I looked online and they are not spyware.

Also, when I looked at services tab (msconfig command), the following are the processes that are there (I'm not including the ones that are labeled under Microsoft Corporation Manufacturer because and I'm thinking those are necessary)
-Apache2 (used this for school)
-HP WMI interface
-iPod service
-LightScribeService Direct Disc Labeling Service
-Office Source Engine
-Remote Packet Capture Protocol v.0 (experimental)
-Sophos Anti-Virus Status Reporter (spysweeper)
-Sophos Anti-Virus (spysweeper)
-Sophos Auto Update Service (spysweeper)
-SoundMax Agent Service
-Webroot Spy Sweeper Engine
-Windows media player network sharing service

There are a few normal activities that can cause a shutdown delay --- closing/purging temporary files is one. Some users set various cleanup tasks to run at shutdown, and that slows things down as well, of course. On system with a lot of RAM and/or a slow hard drive, Hibernation can take a noticeable chunk of time, and so on.

Beyond the more or less obvious, one common cause of shutdown delays is a driver that won't let go; one that does not respond to the "terminate" command from the OS. (Some printer and CDR drivers seem to be especially prone to this.) So, one thing you can do is ensure that all your drivers are up to date with recent, known-good (check the BBSes or Google Groups) versions.

You can also troubleshoot the issue more scientifically. XP has a built in "Startup and Shutdown Troubleshooter" although it doesn't go very far. Still, it's a place to start: Go to Start/Help and Support and use "shutdown" as the search term, and under "Fix a Problem" select the "Startup and Shutdown Troubleshooter."

Many other troubleshooting tools exist, too: http://www.google.com/search?q=trouble+s...

And you also can brute-force a shutdown. The command

shutdown -s -f

typed into the Start/Run line or used as the guts of a batch file will tell the OS to force (-f) a shutdown (-s) even if some software or driver doesn't acknowledge the termination command.

And, for completeness,

shutdown -r -f

does the same thing, but with a reboot (-r) instead of a shutdown. For more about "shutdown" command options, go to Start/Help and Support and use "shutdown" as the search term, and under "Pick a task" select "Shutdown."

when you open that device manager, close ALL processes and it wil shut down. for a permanent fix to your problem, you could run a virus and spyware scan, and a defrag, and then proceed to uninstall any software that you dont use, and if nothing works, format and reinstall it all. It beets taking it somewhere to get fixed and it always works to restart before it gets too late.

I have found that sometimes my print spool program doesn't 'flush' and hangs up the shut-down process.
Try turning the printer off manually and/or reinstalling the printer driver.

I suggest that you try to carryout system restore to a day previous to the day when there was no virus or any problems. It may be a few weeks or months back. You have to decide the date. Detailed instructions are posted at http://fixit.in/systemrestore.html
The problem is likely to be solved. Then,You insatll a standard antivirus soft ware such as Norton, AVG , Avast ( free antivirus software and Ad-aware, Ewido ( free spyware removers). You can download free softwares at
http://fixit.in/antivirus.html and http://fixit.in/spywareremover.html

If your computer is not working properly while you are working on it, it could be a problem with device drivers, hardware or software.
Detailed instructions at http://tinyurl.com/yk5zpr