in my laptop has an windows 8.1 in start menu i cant use any apps or an camera calender etc...., any options  i dono wts the problem if anybody known about these prob pls         inform me     why i cant use this????????? pls help me frndzzzz....

 Try running the Apps troubleshooter. This tool can automatically identify and fix some problems with apps and the Store.

Hi Pravenair027,

Can we get into these apps before? Have you got any error messages? What happened when we opened the Windows Store Apps?

We can take the following steps to have a check :
1.Refer to this link to register the windows store apps to have a check :
Fix Store App in Windows 8.1
http://blogs.msdn.com/b/notime/archive/2013/10/18/fix-store-app-in-windows-8-1.aspx
2.Take the steps in this link to have a troubleshoot:
Troubleshoot problems with an app
http://windows.microsoft.com/en-HK/windows-8/what-troubleshoot-problems-app
3.Run wsreset.exe to clear cache to have a check.
4.If the issue persists, please check the Event Viewer for related information to troubleshoot this issue.
This path may be helpful: Event Viewer>Applications and Services Logs>Microsoft>Windows> AppModel-Runtime ,Apps, AppXDeployment and AppXDeployment-Server

Best regards