====== Windows data recovery and file recovery ======

Important notice:

  - once found data lost, DO NOT do anything to the Computer or Harddisk, any Writing or Use operation can render data recovery impossible.
    * 数据丢失，务必谨记的是不要对丢失数据所在分区进行操作，因为新的数据很可能覆盖丢失数据
  - Never store important Data on C drive (or OS drive) if possible
    * 重要数据不要放置到系统分区，因为系统分区的数据读写是最频繁的,非系统盘数据恢复起来比较容易和完整 
  - Never count on Data Recovery, best practise to protect data is making mutiple copies of backup on your portable usb drive, DVD, or online storage Before bad thing happens.
    * 数据恢复仅仅是尽可能地还原数据,对于重要的数据，日常还是要备份多几份为妙  

===== free recovery tools =====

  - Recuva - http://www.piriform.com/recuva/download
  - FreeUndelete - http://www.officerecovery.com/index.htm#freeundelete
  - iCare unDelete Free - http://www.icare-recovery.com/undelete-free.html


====== Windows problem before Login ======

===== User profile load fail =====

  - Start the computer and press F8 key immediately.
  - In the "Advanced Boot Options" window, select "Safe Mode" and then press "Enter"
  - Login to your account.
  - Click Start
  - In Start Search box, type "regedit", and press "Enter".
  - In Registry Editor window, navigate to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList
  - In the left pane, look for the folder name starting with S-1-5 (SID key) followed by a long number, then click the folder and locate ProfileImagePath from the right pane to verify that this is the user account profile that has the error.
  - If you have two folders starting with S-1-5 followed by same long numbers and one of them ends in .bak
  - Change the .bak folder to normal one. To do this:
  - Right click the folder without .bak and choose "Rename". Then add .ba at the end of the folder name.
  - Right click the folder with .bak and choose "Rename". Then remove ".bak" at the end of the folder name.
  - Right click the folder with .ba and choose "Rename". Then change the .ba to .bak at the end of the folder name.
  - Choose the folder without .bak
  - In the right pane, right click on RefCount and then select "Modify"
  - Under "Value Data", type 0 and then click OK.
  - Right click on State and then select "Modify"
  - Under "Value Data", type 0 and then click OK.
  - Close Registry Editor window.
  - Restart the computer in normal mode.
  - Log on to your account again.