If I understand you correctly, you moved a hard drive with Windows 98 installed to a new motherboard.
You also moved over your plug-in cards.
The PC now only boots into safe mode.
What you have going on, is that Windows is trying to load the drivers for the old motherboard, and since the hardware is not there, it is hanging.
First, make backup copies of config.sys, and autoexec.bat
They are in the C:\ folder.
Copy the existing files to a new folder.
Open System Properties.
Click on the device manager tab.
Expand the branches as needed, and REMOVE ALL hardware that is not part of the new system.
This includes ALL motherboard resources.
Then, Run msconfig
On the startup tab, uncheck process config.sys and autoexec.bat
Click on Apply, and re-boot.
If the system now boots, you need to determine if a driver statement in either file is causing the problem.
Individually uncheck the lines in each file until you find the culprit.
Still having problems, start by installing the motherboard or chipset manufactures drivers for the new motherboard.
After the re-boot, make sure that Windows properly identifies all of the hardware that is installed.
If you still have trouble booting up, the next step is a littlemore drastic, and risky.
CAUTION: improper use of regedit can disable your system. Proceed with caution!!
Run regedit
click on file search, and search for enum
Delete the enum key(s)
Close regedit
Re-boot
Install drivers as needed.
Chas
