1.Right click ->Desktop->Properties->Theme ->select windows classic click apply ->O.K
2.Use NTFS file system If you are using FAT32 then you can convert into NTFS without losing data very easily .But once You have converted FAT32 TO NTFS you will no more going to convert it into FAT32.NTFS Volumes cannot be accessed from opearting systems like win98,Me.you can read the full article at http://support.microsoft.com/kb/307881
3.Disable fast user switching you can do this by start->settings->control panel->user accounts->change the way users logon and off->remove tick mark for fast user switching keeping in mind that only one person is using the computer.
4.Disable Indexing service indexing service is used for searching faster .you can disable this by going to My Computer->right click c drive->and remove the tick mark to Allow indexing Service to index this disk for fast file searching
- Similarly you can do this to all volumes as well You can also do this by start->run->services.msc->stop or disable the Indexing service from service list.
5.More pretty graphics,color more lesser in performance so.go to start->settings->control panel->system->advance->performance ->settings->select adjust for best performance.
6.Remove shortcuts that are not necessary on desktop.
7.Clean temp,%temp% files ,cookies,history and temp.Internet files from your browser run Disk cleanup tool .
8.Need to boot windows faster disable unwanted services.start->run->msconfig ->disable unnecessary services that starts when windows starts be caution to leave anti-virus and system related items .
9.Slow shutdown of your computer will not help so use shortcut buttons to shutdown,restart windows faster .