|thanks for the reply...|
sorry i wrongly stated that it was unaccessible under fdisk. it is after changing the selected disk(option 5 in fdisk) which i kind of missed last time.
ubuntu could recognize my disk. i deleted the partition and opened it up in xp and then i could access it.
i wonder why the XP is unable to load under these conditions .
In xp i had a copy of its old mbr and so i updated it just to again try it.
1. If i kept disk id to 42(dynamic disk) and 00 at other empty partitions, it was accessible via xp
2. If i kept disk id to 42(dynamic disk) and 07 at the next empty partition(just one other ),it was accessible via xp but if i write 07(so total 3) to all the others too then it is UNaccessible not even via fdisk.
3. if i kept disk id to 07(basic disk) and 00 at other empty partitions, it was accessible via xp
4. if i kept disk id to 07(basic disk) and 07 at just one other empty partition, it is accessible but if i do it to all the 3 then it is inaccessible(as in xp doesnt boot) but surprisingly accessible via fdisk!!!)
now i want to know why so.