windows partition help

[Khaos HiDef]

I have windows 8 on my main computer but lately the operation system has been buggy and annoying so i want to do a fresh install but i've missplaced my install disk so alls i have is a laptop with windows 8 64 bit and want to copy that over but how would i do this without data loss since i have about 300gb of files installed on my harddrive

 

[SuperSoph_WD]

Welcome to Tom's Hardware, Khaos HiDef!

You can create a bootable flash drive from your laptop with the ISO file for Windows 8. However, you'd need to the original product key/activation code/ from your genuine PC Windows 8 Installation disk in order to do a total fresh install.
Or you can simply create a Windows Repair disk/USB using your laptop and restore the OS on your PC back to defaults.
Check these links:
http://windows.microsoft.com/en-us/windows-8/create-usb-recovery-drive
http://windows.microsoft.com/en-us/windows-8/restore-refresh-reset-pc

Hope this helps! Good luck!
SuperSoph_WD