cannot upgrade to 13.10

[harikris2000]

Could not calculate the upgrade

An unresolvable problem occurred while calculating the upgrade.

 This can be caused by:
 * Upgrading to a pre-release version of Ubuntu
 * Running the current pre-release version of Ubuntu
 * Unofficial software packages not provided by Ubuntu

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: ubuntu-release-upgrader-core 1:0.192.13
ProcVersionSignature: Ubuntu 3.8.0-32.47-generic 3.8.13.10
Uname: Linux 3.8.0-32-generic i686
NonfreeKernelModules: wl
ApportVersion: 2.9.2-0ubuntu8.4
Architecture: i386
CrashDB: ubuntu
Date: Fri Oct 18 12:03:18 2013
InstallationDate: Installed on 2012-01-14 (642 days ago)
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111012)
MarkForUpload: True
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to raring on 2013-10-18 (0 days ago)
VarLogDistupgradeTermlog: