Preparing network connections = reboot...

Question

Hello.
Im really new to System Center and have gotten the respenoibility in our IT department to configure it and to keep it updatet with the latest drivers for our clients.
Recently we bought a Lenovo ThinkPad T440 laptop. When i tried to reinstall windows 7 using SCCM 2012 i got to the point where it said "preparing network connections" then it disapeared and all i could see was a blank SCCM background. After a few
seconds the computer rebooted.
So what i have tried to do is:'
I downloaded the SCCM driver pack from Lenovo for the T440. Imported it into SCCM, added it to a driver package (wich i made new) and added it to a x64 boot image, since this was the x64 drivers. Simply following the import driver wizard. What i did next
was to distribute the driver package to the DP and then i updated the DP with the boot image.
All the right network drivers are there and i still get the same fault... A rebooting client after "preparing network connections". 
Appreciating all answers and tips :)
Edit: The driver package i found on Lenovo is a driver package for SCCM and is called SCCM Package for windows 7 (x64).

Answer 1

Hello and thanks for so many good answers! You guys are really helpful :)
Now i have cleaned up the boot images and started all over again from scratch. This time i tried to only import the network drivers for the T440, i saw some people before had done that in a different driver package. But when i am trying to update DP, adding
the network drivers to the boot image i get this error message:
  Error: Boot image to update: 
• Microsoft Windows PE (x64)
  Error: Actions to perform: 
• Add ConfigMgr binaries
• Set scratch space
• Enable Windows PE command line support
• Add drivers
  Error: Failed to import the following drivers:
• Realtek RTL8192CE Wireless LAN 802.11n PCI-E NIC(TEST)
• Intel(R) WiFi Link 5300 AGN
• Intel(R) Centrino(R) Wireless-N 100
• Intel(R) Dual Band Wireless-AC 3160
• Intel(R) 82579LM Gigabit Network Connection
• Intel(R) Ethernet Connection I217-LM
• Intel(R) 82567LM-3 Gigabit Network Connection
 Optional components:
• Scripting (WinPE-Scripting)
• Startup (WinPE-SecureStartup)
• Network (WinPE-WDS-Tools)
• Scripting (WinPE-WMI)
  Error: The wizard detected the following problems when updating the boot image.
• Failed to inject a ConfigMgr driver into the mounted WIM file
The SMS Provider reported an error.: ConfigMgr Error Object:
instance of SMS_ExtendedStatus
• Description = "Failed to insert OSD binaries into the WIM file";
• ErrorCode = 2152205056;
• File = "e:\\nts_sccm_release\\sms\\siteserver\\sdk_provider\\smsprov\\sspbootimagepackage.cpp";
• Line = 4566;
• ObjectInfo = "CSspBootImagePackage::PreRefreshPkgSrcHook";
• Operation = "ExecMethod";
• ParameterInfo = "SMS_BootImagePackage.PackageID=\"VN200005\"";
• ProviderName = "WinMgmt";
• StatusCode = 2147749889;
Does anyone know what i have done wrong this time?
I have also now tried the IPCONFIG command and all that appears is Windows IP Configuration... nothing else.. and i can type /all because of my Norwegian keyboard.. and i have no idea where i can find the /.. :P
Edit: The drivers i have imported are for windows 7 and the boot image OS version is 6.2.9200. Is this wrong? The Error does not longer occur and i have succesfully updated the DP. But still, it reboots after "Preparing network connections".