recover partition after reinstall windows XP

My OS was infected by trojan or virus and system files are corrupted. After tried to reinstall XP several time and failed, I took out the hard drive and prepare to back up files for a clean reinstall. Then found my data partition (D:) was empty except only a pagefile.sys, but looking into property, still can see 80% of disk space used (80GB).

It seems the index or something was corrupted during rebooting "chkdsk" when doing recovery installation. I found the disk label has been changed and chkdsk was reindexing that partition. But it hang somewhere so I forced reboot the machine. Could anyone help me out how to fix this?

PS: below is message from chkdsk: Stage(2 of 3) Correcting error in index $0 for files 25. Index verification completed. Error found. CHKDFK cannot continue in read-only mode.

http://www.piriform.com/recuva Is a free tool made by the makers of CCleaner.

It's worth a shot and certainly doesn't cost any money.

ddrescue is another very powerful option but it's more gear toward linux professionals. It works wonders.

WinHex or the 'lite' variant Davory would be my tool of choice, state-of-the-art forensic utilities.

you can run Davory over the drive and see if it is able to find your files. however, you will have to purchase a license in order to recover the files.

Note: When you select the drive to scan (F9), choose the physical disk rather than the logical drive.