Uninstall hidden Windows components

Apparently, Microsoft didn't want you to be able to remove useless garbage like Windows Messenger. It's installed by default, and it doesn't appear in the Add/Remove Program applet in Control Panel.
Thankfully, you can force the issue by editing the SYSOC.INF file, which is located in the C:\WINDOWS [or your Windows XP directory]\INF folder. Open it with Notepad.

Under the [Components] heading, you'll see a whole bunch of parameters for various Windows applets. Some of them contain the word "hide." Those particular programs, which include Windows Messenger (msmsgs), Terminal Server, Pinball, and others, are installed on your XP system, but their entries are hidden from and Add/Remove dialog.
To remove Windows Messenger, edit hide out of the line that reads

msmsgs=msgrocm.dll,OcEntry,msmsgs.inf,hide,7
so that it looks like this:
msmsgs=msgrocm.dll,OcEntry,msmsgs.inf,7
Save the file, close it, and open the Add/Remove Program applet. Click on Windows Components button and you'll see Windows Messenger listed. Uncheck it and click Next to purge that silly program from your system.
Feel free to edit hide everyw
here it appears in the SYSOC.INF file to reveal other removable Windows XP components.
Offer DMA To All Your ATAPI Drives
By default, slave drives on ATAPI channels are often set to PIO mode--even when the device attached is capable of much more efficient UltraATA (or DMA) mode data transfers. This can hurt the performance of ROM burners, DVD movie playback, and other drive functions. Plus, DMA mode data transfers require much less CPU overhead than PIO-mode transfers.
You can set this atrocity straight through the Device Manager. Open the System Properties dialog and select the Hardware tab. Click the Device Manager button. Expand the entry for IDE/ATAPI controllers.
Select the primary channel and click on Properties, and then choose the Advanced Settings tab. For each device listed, change the transfer mode to "DMA if possible." Don't worry; devices that aren't capable of DMA mode will still work just fine. Repeat the process for the secondary channel.