It is pretty hard for me to tell you what is wrong when you say it just locks up.
What was happening when it occured, what happened, you say it locked up, was there any messages first, did it go back to desk top ...
What are your computer specs?
This is really only a HOI support forum, however I may be able to help, but remote diagnostics can be very hard to do.
If you are not confident with computer hardware, you may want to consult with where you had the upgrade done. They would know your system better than I. And parts may still be under waranty.
What was happening when it occured, what happened, you say it locked up, was there any messages first, did it go back to desk top ...
What are your computer specs?
This is really only a HOI support forum, however I may be able to help, but remote diagnostics can be very hard to do.
If you are not confident with computer hardware, you may want to consult with where you had the upgrade done. They would know your system better than I. And parts may still be under waranty.