Problem if I switch parts in a pc

[Gotland14]

Can i get problem with the computer if I´m switching parts?
I've Heard that some people got problems when they changing parts.

 

[USAFRet]

Depends on what you are changing.

You might need to reinstall Windows. If you have an OEM version, it may not reactivate.

It all depends.

 

[Gotland14]

What is a OEM version ?

 

[USAFRet]

OEM = if you bought the PC with Windows already installed. Dell, HP, or other.

If you bought the copy of Windows yourself, it may be either OEM or retail.