Partition C:\ is not recognized by computer

Problem; Partition C:\ is not recognized by computer
Question; how can I restore partition C:\ or at least access it again?

Detailed description;
I have a C, D and E partition on my computer. I realized that C was a bit to big, so I decided to transfer 1 Gigabyte of free space from C to D. Partition magic started the proces, rebooted, but resulted in a blue screen. After using the XP-option to reset the system to an earlier configuration, I was able to start windows again. Partition magic showed that the space had been removed from C, but the space wasn't moved to D...instead, it had created a fourth seperate unassigned space.

Therefore, I tried run Partition Magic again, in order to recapture this lost space. But after rebooting, the screen turned blue, delivering the following message; "inrepairable system error, system proces initizialization failed".

I managed to install XP on another harddrive, therefore, I was able to access the original harddrive. It shows only the partition D and E.

My question; the C drive contains a large amount of delicate info. Off course the best solution would be to restore the C drive to it's original state, but I realize this might not be possible. Though I hope it's at least possible to gain access to this partition, in order to copy the information on it?

I guess I need somekind of 'standard' sector-file to put on the C:\ drive in order to be able to access it... or I'll need to format, but without deleting the content (is this possible?)

Please Help!