Dynamics AX 2009 Upgrade

i want to upgrade from ax 2009 to AX 2012 R2 and i am stuck on this error,

when i click…

Preprocessing upgrade checklist>>Configure partitions# the following error appears:

Request for the permission of type ‘SqlStatementExecutePermission’ failed.
(S)\Classes\SqlStatementExecutePermission\demand
(S)\Classes\Statement\executeUpdate
(C)\Classes\ReleaseUpdatePartitionsMappingDatabase\createDefaultPartition - line 50
(C)\Classes\ReleaseUpdatePartitionsMappingDatabase\initPartitions - line 8
(C)\Classes\ReleaseUpdatePartitionsMappingDatabase\initMappings - line 8
(C)\Classes\ReleaseUpdatePartitionsMapping\initMappings - line 4
(C)\Forms\DEL_ReleaseUpdatePartitionsMapping\Methods\init
(C)\Classes\SysSetupFormRun\init - line 3
(C)\Classes\MenuFunction\run
(C)\Classes\SysHelp\processMenuFunction - line 85
(C)\Classes\SysHelp\processStandardLink - line 18
(C)\Classes\SysHelp\processOnEventNavigate - line 40
(C)\Classes\SysHelp\onEvent_BeforeNavigate2 - line 27
(C)\Classes\FormActiveXControl\onEvent_BeforeNavigate2

I have seen some solutions to this but i need a step by step guide on ow to solve this error,i am a novice