The best replacement for bitlocker is truecrypt.

The best alternatives to bitlocker are rated as following:
★★★★★  truecrypt
★★★★  efs
★★★  pgp
★★  bitlocker to go
★★  pointsec
★★  safeboot
★  mcafee endpoint encryption
★  filevault
★  checkpoint
★  credant
★  sed
★  safeguard
★  hardware encryption
★  mcafee encryption
  guardianedge
  becrypt
  dell data protection
  tde
  encryption
  pgp wde

Your alternative for bitlocker is not listed? Suggest!
Speaking about bitlocker, one probably shouldn't forget about tpm.

Other search terms related to bitlocker and their ratings are:
★★★★★ tpm
windows 7 ultimate
You have in mind a companion for bitlocker and it is not yet here? Propose!



Google Trends

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bitlocker
truecrypt
efs