repairing win xp

i have a dual partition of win 98 and win xp pro on my computer.just recently by mistake i disabled my administrator account of win xp and now i can’t logon to win xp, however i can use win 98. as i cannot logon to win xp it is not possible to run the repair setup from win xp.is there any way of repairing win xp without loging on to win xp?Please help.