Here is the way:

Run REGEDIT and go to HKEY_CLASSES_ROOT\Directory\Background\Shell. Right-click the Shell part, select New > Key and call it
Aero On.

Right-click the Aero On key you’ve created, and create a new key called command. Double-click this (in the right-hand side of the screen) and give it the value Rundll32 dwmApi #102.

Right-click the Shell key again, select New > Key, and call this Aero Off. Create a command key below it, as you’ve just done, and give it the value Rundll32 dwmApi #104.

Now, right-click an empty part of the desktop to see your options, and select Aero On when you want fancy effects like Flip 3D, and Aero Off when you’re after raw speed.

Read full article here.

System Preparation: Tweak Insurance (1-3)

1. Back up and restore Windows Vista Registry
2. How to edit the Windows Vista Registry
3. Creating a system restore point in Windows Vista

System Preparation: Hardware (4-10)

4. Add more memory (RAM)!
5. Update the motherboard BIOS
6. Update hardware drivers
7. Test the Computer’s RAM
8. Optimize the memory timings and voltage
9. Overclock the processor and memory
10. Overclock the videocard

First Boot – The Essential Tweaks (11-20)

11. Turn off User Account Control (UAC)
12. Set Automatic Update to download only
13. Learn to use the search bar as a Run command.
14. Disable automatic device driver searching and installation
15. Use Windows Defender to disable startup programs
16. Power options to high performance.
17. Enable DVD playback in Vista Basic and Vista Business.
18. Make the 64-bit version of Windows Media Player 11 the default player in Windows Vista x64
19. Update vista!
20. Run programs with administrator rights

Windows Vista Performance Boosting Tweaks (21-53)

21. Disable search indexing
22. Limit start menu search options
23. Remove remote differential compression
24. Boost external hard drive performance
25. Enable Readyboost on any flash memory device.
26. Speed up SATA drives in Vista.
27. Assign specific CPUs to applications
28. Assign priorities to applications
29. Create shortcuts for running applications with certain CPU/Priority settings
30. Disable unnecessary services
31. De-automate Windows Defender
32. Upgrade to Vista Service Pack 1 Beta (SP1-beta)
33. Disable superfetch for computers with less memory
34. Boot Vista with all available processors
35. Force 32-bit Windows Vista to use all your memory by enabling PAE
36. Used advanced disk cleanup tools to regain more space
37. Shut down services faster for faster shutdown.
38. Disable the Vista sidebar
39. Set the Sidebar to low priority
40. Kill the RSS feed sidebar gadget
41. Disable automatic backup/system restore
42. Disable hibernate on desktops
43. Stop scheduled disk defragmentation
44. Move the Vista paging file for better performance
45. Set a fixed paging file size
46. Rebuild the paging file to optimize performance
47. Move search index to another physical drive
48. Disable the low disk space check
49. Disable 8.3 name creation
50. Disable last access file update
51. Disable unneeded hardware
52. Check bootup and shutdown times with the Windows Vista Event viewer
53. Check your system’s health in 60 seconds or less

Mastering & Streamlining the Vista Interface
(54-83)

54. Use checkboxes for multiple file selection
55. Enable Windows classic desktop appearance
56. Reduce start menu opening delay
57. Disable mandatory thumbnail previews
58. Remove unnecessary Windows Vista features
59. Start task manager directly
60. Run sidebar gadgets without the sidebar
61. Backup your entire computer with Vista Backup and restore (Vista Business and Ultimate only)
62. Essential hotkey shortcuts for Vista
63. Return the run command to the start menu
64. Using the new ‘resource overview’ monitor in Windows Vista
65. Use the Vista reliability checker to track system issues
66. Disable warning sounds and add visual cues
67. Create desktop shutdown and reboot icons
68. Good sidebar gadgets to have (and not to have)
69. Run any application as administrator with a few keystrokes
70. Configure Windows Vista autoplay manually to suit your preferences
71. Disable security notifications
72. Tweak the mouse scroll wheel
73. Add Encrypt / Decrypt to Right Click Menu
74. Disable ‘GUI boot’ to speed startup
75. Add administrator account to welcome screen.
76. Change volume levels for individual applications
77. Display your backed-up DVD media in Vista Media Center (applies to Vista Home Premium and Ultimate only)
78. Reveal Vista’s hidden context menu power tools
79. Be the super user
80. Fix the Start Menu Power button
81. Enable verbose shutdown messages (Vista business and Ultimate only)
82. Customize Vista desktop performance
83. The ultimate Vista performance Tweak (not really)

‘Aero’-Dynamics – Customizing the Vista Aeroglass Interface (84-86)

84. Disable Aero (All versions except Vista Basic)
85. Disable Aero transparency (All versions except Vista Basic)
86. Disable min/max window animation in Aero (All versions except Vista Basic)

Network & Internet Performance Tweaks
(87-91)

87. Enable more simultaneous downloads in Internet Explorer 7
88. Enable more simultaneous Downloads in Firefox
89. Fix large file copying problems in Windows Vista
90. Disable IPV6 in Windows Vista
91. Refresh shortcut for wireless network searching

Vista Tuning Tips for Notebooks (92-94)

92. Disable Transient Multi-monitor manager to speed up boot times
93. Tweak your Vista power saving options for more travel time
94. Disable Aero interface to save big on battery life

Windows Vista Gaming Tips (95-99)

95. Update Vista’s DirectX9 files for better game compatibility
96. Disable background features while gaming
97. Run directX 9 games in Windows XP compatibility mode
98. Fix/enable 3D sound in some games
99. Poor game performance? Try DirectX9 mode
Exact url of the article: http://www.pcstats.com/articleview.cfm?articleID=2238

That’s All!

To disable this constant indexing:

* Click Start then Computer
* Right Click the C: Drive
* On General Tab, Uncheck Index this drive for faster searching
* On the subsequent dialog box, Select Include subfolders and files

2. Turn off Remote Differential Compression
Remote Differential Compression measures the changes in files over a network to transfer them with minimal bandwidth rather than transferring an entire file that has previously been moved. By constantly checking for file changes, this service can hinder system performance.

To disable this service:

* Open Control Panel
* Switch to Classic View
* Select Program Features
* Choose Turn Windows features on and off
* Scroll down and uncheck Remote Differential Compression

3. Turn off Automatic Windows Defender Operation
Windows Defender real-time protection against malware continues to run despite having Automatic operation disabled.
To disable this feature:

* Open Control Panel
* Select Windows Defender
* Choose Tools from the top menu
* Select Options
* Uncheck Auto Start at the bottom of the window

4. Turn off Automatic Disk Defragmentation
Windows Vista and its always-on defragment feature isn’t really that necessary and can cause system slow down. Just remember to run a defrag manually every week or so.

To disable this:

* Click Start then Computer
* Right Click the C: Drive
* Select the Tools Tab
* Uncheck Run on a schedule

5. Add a 2GB or higher USB Flash drive to take advantage of Windows Ready Boost (Additional Memory Cache)
Ready Boost is Microsoft’s name for using a USB thumb/flash drive to provide some quick access memory the operating system can use as extra RAM. The Ready Boost system can significantly improve system performance.

To set this up:

* Insert a USB Flash Drive (preferably 2GB or more)
* Click Start then Computer
* Right Click the USB Drive in My Computer
* Select the Ready Boost Tab
* Choose Use this device
* Select as much space as you can free up for RAM usage vs. Storage

6. Turn off Windows Hibernation
Windows hibernation background services can use a large amount of system resources. If you don’t use the Hibernate feature on a regular basis you may want to disable it to give Vista a performance boost.
To disable Hibernation:

* Select the Control Panel then Power Options
* Click Change Plan Settings
* Click on Change Advanced Power Settings
* Expand the Sleep selection
* Expand the Hibernate After selection
* Crank the selector down to zero
* Click Apply

7. Turn off System Restore
Analysis and restore point creation by Windows Vista can eat a fair amount of system resources. Disabling this service will obviously mean the system restore feature in Vista will not be available in the event of a system crash. Change this at your own risk.

* Control Panel>System
* Click System Protection on the left panel
* Uncheck the main system drive
* Agree to the confirmation

8. Disable User Access Control (UAC)
This much-loathed new Vista feature attempts to protect your system from malware infection by making you manually confirm a whole host of everyday user operations. While it doesn’t directly impact performance, it can be annoying and might be more hassle than good.

To disable User Access Control:

* Click Start then Control Panel
* Select User Accounts
* Select Turn User Account Control on or off
* Uncheck User Account Control Box
* Restart as recommended

9. Disable excess Windows Services that Auto-Launch at Startup
Just like Windows XP, Vista ships with all kinds of services enabled that load at startup and may never be used by most users.
To see what loads at startup and disable the ones you likely won’t be needing (they can always be started manually later):

* Click Start then Control Panel
* Select Administrative Tools
* Choose System Configuration
* Click the Services Tab
* You can safely deselect:
- Offline Files (unless you’re using Offline File Sync)
- Tablet PC Input Service (unless you have a tablet PC)
- Terminal Services
- Windows Search (If you have already disabled indexing)
- Fax (unless you’re using a fax modem)

10. Disable Excess Windows Features
Windows ships with other features that are listed separately in the Vista operating system from the startup services.
You can view and disable these features by:

* Clicking Start then Control Panel
* Select Program Features
* On the left panel, select Turn Windows Features on or off
* You can safely deselect:
- Indexing Service
- Remote Differential Compression
- Tablet PC Optional Components
- Windows DFS Replication Service
- Windows Fax & Scan (unless you use a modem for faxing)
- Windows Meeting Space (unless you use the Live Meeting Service)