I am going to remove XP from my D drive where also boot for 7 is residing.
I will use 2.0 for this. My question is how to recover if something goes wrong?
Which files should I backup to be able to restore?
where is your BCD store? HDD "C"?
Where are the Boot information? HDD "C"?
Then you can with EBCD 2.0 delete the XP entry in the BCD and delete the XP partition.
If one Boot-Part for Win7 on the XP partition, you have more to do.
Get the latest version of EasyBCD here. Go to BCD Install/Repair > Change Boot Drive and point it to W7. Remove XP's entry. Now reboot and if W7 boots without any issues you can safely do whatever you want with XP's partition.
If XP is not marked "system" in Disk Management, you can just format the partition.
If XP is "system", then use EasyBCD latest build
Change Boot Drive
Point it to W7 when asked
(if the systems are on different HDDs, change the BIOS to boot from the W7 HDD)
Check that W7 is "system"
format XP when you're finished with it.