If using Windows XP Professional:
1. Click Start - Run - type GPEDIT.MSC and press Enter key
2. Expand to:
User Configuration
Administrative Templates
Start Menu and Taskbar
3. In the righ-side pane check for the entry called "Force classic Start
Menu".
4. if it is set to "Not Conifgured" or "Enable" then double-click the entry
and set it to "Disable".
For both Windows XP Home and Professional
1. Click Start - Run - type REGEDIT and press enter key.
2. Here Expand to:
HKEY_CURRENT_USER\SOFTWARE\MICROSOFT\
WINDOWS\CURRENTVERSION\POLICIES\EXPLORER
3. In the right side pane check for entry name called "NoSimpleStartMenu".
4. Right-click the entry and click Delete.
Hope this solves your problem, let us know!