If a computer administrator has disabled Task Manager in your user account, you’ll see the message Task Manager has been disabled by your administrator when you try to start Task Manager. If you are an administrator, and the restriction wasn’t intentional, you can reactivate Task Manager through the registry.

Here’s how :

• Never experiment with the registry settings. Back up the registry before making any changes.
  
• Click the Start button, and choose Run, or press Start+R.
  
• In the left column, navigate to the following key:
  

          HKEY_CURRENT_USER\Software\Microsoft\Windows\           CurrentVersion\Policies\System

• The key is only available on systems where Task Manager has been disabled through Group Policy.
  
• In the right pane, double-click DisableTaskMgr, and set its data value to 0.
  
• Exit the Registry Editor.
  

Open up registry editor, by Click Start – run then type regedit
Go to the following key

HKEY_CURRENT_USER\Software\ Microsoft\Windows\ CurrentVersion\Policies\Explorer
Create a new DWORD value on the right pane with the following values Name

NoUserNameInStartMenu

Value: 1
To remove, either set the value to 0 or just delete the key. You will have to log off and back on to see the start menu without the username:
You could also remove the picture by deleting or renaming this folder

C:\Documents and Settings\All Users\ Application Data\ Microsoft\User Account Pictures\Default Pictures

Doing so would remove the picture from the login page as well, and it doesn’t remove the blue border across the top.

-Speed up your PC’s performance.

Windows Vista introduces a new concept for adding additional performance to a running system. Windows ReadyBoost™ lets people use flash memory on a USB 2.0 drive, SD Card, Compact Flash, or other memory form factor to provide additional memory cache—memory that the computer can access much more quickly than it can access data on the hard drive. Insert a USB 2.0 memory drive with at least 512 MB capacity. When prompted, click use this device to speed up my computer.

-Recover a previous version of a document.

Windows Vista introduces a new feature: Previous Versions. This allows you to “roll back” the clock to an earlier version of a file that you may have accidentally saved over or edited. In the Documents Explorer, open a document, edit it, save it, and then close it. While selecting the document, choose the Previous Versions option on the command bar, which will bring up a list of previously saved versions of the individual file. Choose a previous version and Windows Vista will restore your file to that version. Careful: all edits since that version will be lost.

-Browse multiple Web sites.

Tabbed browsing in Internet Explorer® 7 enables a single Internet Explorer window to run with the convenience of multiple pages. Open a new page by clicking the empty tab on the toolbar or by right-clicking any hyperlink and choosing New Tab. Tabs can also be right-clicked to refresh individual pages or refresh pages as a group. You can close either individual tabs or an entire group, and you can save tabs as one favorite group. With the Quick Tabs feature, the icon just to the right of the Favorites icon, thumbnail images of all open tabs can be seen in a single view helping you manage multiple open tabs.

-Print picture perfect Web content.

Most Web sites are simply not formatted to fit cleanly on a standard piece of paper. With the new shrink to fit printing feature found in Internet Explorer 7 Web sites will no longer get cut off when sent to the printer.