I recently set up an iSCSI target on my Synology DS212j network attached storage, and connected via the iSCSI initiator in windows 8.1. I had no problems setting the connection up initially and the drive appears to work fine when connected. However, any time the computer reboots, Windows fails to reconnect to the target automatically, even though I checked the box to remember the connection under favorite targets. I have tried removing the CHAP authentication and the result was the same. I have also tried setting the Local Adapter and Source IP Address in the Target portals to no avail. After a reboot, all I need to do is open the iSCSI initiator and re-connect, but I need this to happen automatically. 

 Thanks in advance for any advice you might have in solving this issue.

Hi,

Firstly, please make sure your Microsoft iSCSI Initiator Service is set to Automatic start.

Seccondly, I found another thread that had similar problem with yours, you can take its sloution as reference.

http://social.technet.microsoft.com/Forums/windowsserver/en-US/ff26e741-0e2d-47f9-9132-859750ef1514/windows-2008-iscsi-does-not-automatically-connect-to-targets-after-reboot?forum=winserverClustering

In addition, please refer to the blog below for more reference to set ISCSI connect automatically after system reboot.

Managing iSCSI Initiator connections with Windows PowerShell on Windows Server 2012:

http://blogs.msdn.com/b/san/archive/2012/07/31/managing-iscsi-initiator-connections-with-windows-powershell-on-windows-server-2012.aspx 

I had the same problem (on 8 and 8.1, x64) and it seems that Windows has issues when using the automatic setup.

The solution is to follow the linked guide starting from Go to the control panel or server manager and find ISCSI initiator + to adjust the settings as shown on the image: