my lap top is dell it was working properly but suddenly stopped working especially opening in normal mode after booting the window opens and the icons are on the screen but when i click to open it remain synchronizing and could not open the files but when i try in safe mode it works well
Do anti-virus/malware scans from safe mode.
If you know the runtime program delaying the boot, disable it from msconfig in safe mode. Hit ctrl+alt+del in Normal mode and go to task manager (make sure "show processes from all users" is clicked) sort by CPU usage and see what is eating up the most resources. You can also disable indexing (used for fast file searching). Clean up your temp folders. Delete pagefile.sys. (it will rebuild on your next boot but goes corrupt once in a while)