So, I currently have a setup of mandrake 10.1 running on two 80 gig HD's, one of which I just put in, so it is unpartitioned. I installed it hoping that I could install a copy of windows to run a windows-only program I needed for work. Unfortunately, during installation, I chose to Quick erase the wrong disk, ie. the one with all of my files. Can anyone please help me with recovery?!? as it stands, I have just hosed my main computer full of all my files, and help would be greatly appreciated!

What is "quick erase"?

Don't do ANYTHING to that drive until you have a plan....

Chances are good that your data is intact---the typical erasing, partitioning, etc. only affects the pointers to the data.

There are utilites out there for data recovery--including free ones--but I have no personal knowledge. You may be better off using a data recovery service.

Before you sned the drive to anyone--and especially before trying anything yourself--make a clone of the whole drive.

Go get a Knoppix liveCD and use "testdisk".

I agree Knoppix has some great tools for fixing partition tables, use all of the tools cross reference the data you retrieve. Then rebuild the partition.

I've done this myself when some weird stuff happened when I had to reinstall windows on another disk ( damn work ), and it decided to rewrite the partition table for my linux disk, because the linux disk was primary master, windows changed the bootloader ( I had boot disks ready, becuase it will always do that ) but what I wasn't expecting was it replacing the partition table, which was a heart attack moment.

Knoppix fixed that up but be prepared for the work.

allright, thanks for the help, I am downloading knoppix now

I had the same problem with Windows.
My partitions were gone.
But then I remembered +/- of how my HD was partitioned.
It looked like this

HD with 80G

HDA1 Windows 5G VFAT
HDA2 Windows 35G
HDA5 Extended 40G
HDA6 SWP 256M
HDA7 / ReiserFS 5G
HDA8 /company 10G
HDA9 /songs the rest of HD

So I knew that my company's data was on a partition between 45G and 55G of the HD.
Then I made this:
New installation of LINUX
HDA1 Windows 5G
HDA5 Extended 75G
HDA6 SWP 256M
HDA7 / ReiserFS 5G
HDA8 /company ReiserFS 55G
HDA9 /recovery ReiserFS 15G

So all my old data should be in de "new" "/company" partition.
Log in as ROOT and install the program to (in this case HDA9 /recovery)
Please check the man page (man foremost) for details and your needs!!!!!!!

I executed this:
./foremost -v -s 50000000 -T -t jpg doc pdf -i /dev/hda8

The program started with search after block 50.000.000 created a folder with timestamp in /recovery and recovered JPGs PDFs
and DOCs

Good Luck!!!

Yes, if this data is really important make a clone firat as pixellany suggested. After that I'd recommend to start with gpart.