If you have Windows 7 installed, it could just work.
A few things to keep in mind, though:
- Backup your data (probably not necessary, but can't hurt)
- I would advise that you check your BIOS and your hard drive settings
first (AHCI/RAID/SATA/ENHANCED). Match the hard drive settings to the old PC's BIOS
- Uninstall all drivers that have an
installer. Graphics card, mobo, sound card... every driver you can
uninstall from "Add/Remove Programs" in Windows.
- Be VERY careful when handling hardware in the exchange process.
Hook up your components and pray.
If it works: install new drivers.
If it does not: make sure you backed up everything before, and install a fresh version of Windows on your new computer. You can also just put the components back in your old PC if that's what you need.
Note: If you had OEM Windows installed on the old PC. Your licence will not work on the new hardware. OEM windows binds to the hardware you activated your licence on. Windows will prompt you for a new key and activation if you had OEM Windows on your old PC.