LinuxQuestions.org - How to recover data on a RAISERFS formatted harddisk

I have a Linspire OS that i had downloaded from some site which is only one CD. I tried installing it on my AMD K6 machine (A pro 2200) but this was a total disaster. First, the installation could'nt go beyond 75%. It generated an error code 200 .... rsync failed. Well since I was running a dual boot of Windows XP and Windows 98, i decided to go back to my good old Windows. Windows worked well.
I discovered i had installed the Linspire on a slave hard disk that had many of my vital data and programs. What a blunder. I thought i had installed it on a partition on the bigger disk. Now this backup drive is a 4GB hard disk. Linspire partitioned the disk and Raiserfs was chosen as the file system.
I booted the computer with a Knoppix live CD so that i could see the contents of the hard disk. (Remember the installation of Linspire had failed at 75%) The hard disks' linspire files were visible but all my data was gone (obviously) ;-(
Now can anybody out there give me a solution of how to recover my much coveted data? I know in technology nothing is impossible.

The 4GB disk where i had installed the Linspire can't boot because the installation failed at 75%. And this is the disk with the data i want to recover. Before installing Linspire with Raiserfs, the hard disk had a FAT32 partition.
Anybody please? Any software that can handle this gigantic task? All help will be adored.
And which open source OS can run successfully on my computer? The computer has an AMD k6 processor called a pro 2200 and a DDR memory of 256MB. Windows and Knoppix reports the speed to be 1100 MHZ.