Change the Number of Recent Items Shown on the Vista Start Menu
If you've ever wondered how to configure the number of documents shown on the Recent Items menu, you've found the right article. The default value is set to show 10 documents, but you can increase that with a registry tweak.
What we are changing here is the amount of documents shown in this menu (I changed mine down to 1 for illustration)
Manual Registry Tweak
Open up regedit.exe through the start menu search box, and then navigate down to the following key, creating it if it doesn't exist.
HKEY_CURRENT_USER\Software\Microsoft\Windows\Curre ntVersion\Policies\Explorer
Add a new DWORD 32-bit value named MaxRecentDocs into the right-hand pane, and then double-click to open it up.
To set the value, you'll first need to change Base to Decimal, and then you can enter any value you want. For instance, if you want to set it to 50, enter that into the Value data field.
Now I'm not entirely sure what will happen if you set it to a huge number… I'd stick with something like 20.