Win 98 's Fat32 file system cannot see win XP's NTFS file system. That is why win 98 does not see the drive. Heres a program that will let you see and save the files to another disk.http://www.programur...ntfs-reader.htm
Usually constant reboots are caused by bad software. One thing i know causes this problem is installing Nvidia newer drivers without uninstalling the old drivers first. I know because i've done it twice.http://www.smartcomp...r...1.asp&guid=
See if you can stop the rebooting by hitting the F8 key while the computer is starting up . If you do get to the choices try safe mode. I personally do not like trying the recovery console as i have found you have many other problems like extra users when you get done. Last choice is reinstalling XP over a reformatted drive.