Data Hard disk not reflected after installing Viats Home Basic

I installed Vista Home Basic on my C drive. Installation was OK. But after
installing the drivers, I found that my data harddisk is not reflected (no
Drive letters, I previously partioned them into D and E drive). But under
Device Manager the Hard disk is shown thee, and that there are no problems
associated with it. I am not able to do anything with my data haiddisk. It is
somehow just not "present".

Using Disk Management ( I somehow stumbled upon it somehow but now am not
able to find it) I do not have the option to Reactivate it as stated in the
troubleshooting guide. What can I do now ? I need the data inside my hard
disk !!