My hard disk has 160 gb when I formatted it showed 127gb I want my memory to get back so what should I do,starting only it is showing 127 gb and now I am left out with only one hard disk drive please suggest me what to do?

Google this,
It happens to most people trying to use large harddrives the cpu bios caps off at 127gb. You can use a program like partionmagic to fully unlock it, but typically it requires it to be reformated completely...
Best of luck

Looks like the bios does not recognize drives over 137 Gig. There is a Microsoft fix (http://support.microsoft.com/kb/305098)if you are using Windows 2000, and another fix here (http://support.microsoft.com/kb/303013) if your are using Windows XP with SP1. Update to SP2 will include the fix.