The trick is to understand the filesystems on the disks.
XP works with FAT32 and NTFS.
Linux works with VFAT (VFAT32), so if your original filesystem was VFAT in linux, you should be OK, and odds are you were not using VFAT (see the mount command man pages on linux for more info).
There is not a lot of reliable freeware (that I know of, because I have the same problem!!) for XP that allows XP to READ and WRITE an EXT2 (or similar linux filesystem).
I would love to be able to do this and they only way I know how (at the moment) for R/W access (free) is to:
(1) mount your disks on a linux server (or build a new one).
(2) create a VFAT32 file system on a partition or new disk.
(3) copy the stuff you want (on XP) to the new VFAT32 partition or disk.
(4) move (new disk) to XP and access that file system from XP.
Please keep in mind (of course) that the linux executables will not execute
but you will be able to read and copy files, etc.
FWIW: here is another commerical program that is advertised to do the trick (that I've been thinking about buying for a few months ...)
http://www.partition-manager.com/n_ext2fs_main.htm
The demo version will allow READ ONLY access to LINUX filesystems that are under 1GB... so if you have really small disk partitions (by todays standards) this would be 'FREE' and you could then transfer the files....
Direct link to demo below:
http://www.partition-manager.com/n_ext2fs_trial.htm
Note: if you download and try this (or buy it), please post back and let us know how it works!