Will converting my first partition to EXT4 make me lose boot info?

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http://askubuntu.com – I recently switched from Windows to Lubuntu as my sole OS. My filesystem now has a NTFS partition with all my data (which I now would like to convert to EXT4), a EXT4 partition with Lubuntu on it and a swap partition. I have a full backup of the data, so wiping the NTFS partition is not the problem. But I want to be sure that, after wiping/converting it I can still boot Lubuntu just as before. The data partition is the first partition and gparted shows me a 'boot' flag on it. Here is my boot info output: http://paste.ubuntu.com/1548312/ Can I just delete the partition, and create a EXT4 (HowTos)