At work I was given a 'new' laptop which was an old Dell i5 with 8GB RAM, 250GB HD and a used Windows10 build which obviously was bloated with junk from the old owner even though a new account had been created for me. Fresh this could have been a great machine and as a fan of Linux for home use I decided to take the jump on my work machine too. A great decision but the problem was the Windows build was encrypted and I wanted to keep that for the company software, which I never used for work or during the normal work day but had to occasionally.

The answer was a dual boot machine, original Windows 10 for the company stuff and Linux for real work, the following are the steps I followed:

Convert new laptop to dual boot.

1. Turn off hibernate, see here (or local backup)
2. Turn off bitlocker, see here (or local backup)
3. Apply any outstanding updates
4. Clean disk and delete all cache and temp files
5. Defrag, check free space to ensure you have enough for the Linux partition
6. Shrink partition accordingly to make space for Linux on the drive
7. Backup Windows to USB, so as to not lose settings or keys, just in case
8. Boot off Linux USB and install Linux along side Windows with encrypt home drive option (for work)