Hp pavillion not recognizing SSD

[Uheddy]

I have a hp pavillion (its a little older, doesnt have sata) and i bought a sata to usb cable to plug in my ssd from my other machine (which has windows 10 installed) and when i boot the hp with the ssd installed it says 'Boot device not found please i stall an operating system on your hard disk' Any suggestions? Thanks in advance

 

[bjornl]

You can only boot from a HD that was installed on an absolutely identical PC.
So if you installed Win10 on a HD, attach it via USB to your new PC and try to boot from it, it won't work.

If on the other hand you are just trying to move files between PCs you should just use your local network for that.
If you want the SSD to be a permanent 2nd HD in your older PC, then check your BIOS and make sure it is set to boot from your internal HD first.