Upgrate and Installation problem

[kalanithi]

Hello Sir,
             I have worked in joomla 2.5.28 and Virtuemart 2.6.14 working fine but Today I have upgrade joomla 3.4.0 and Virtuemart 3.0.6 my shop is not working.
My virtuemart not install please check below issue,How to solved?   please help me,
Warning
JInstaller: :Install: Can't find Joomla XML setup file.

JInstaller: :Install: Can't find XML setup file.

Duplicate column name 'custom_desc' SQL=ALTER TABLE `t2c_virtuemart_customs` CHANGE COLUMN `custom_field_desc` `custom_desc` char(255) COMMENT 'description or unit'

[GJC Web Design]

have u unpacked the http://dev.virtuemart.net/attachments/download/913/com_virtuemart.3.0.6_extract_first.zip to the 2 separate files?

Have u tried a "manual" install in Joomla (unpack and ftp to tmp folder - run from there-- Google this)  ?