In Quickbooks, I Can Only Access Vendors, Customers, Employees With Names A-s. I Can’t Get T-z, Please Help???

I am taking over a/p, and when vendors call and ask questions, it is very difficult to see any info when they are not on the screen. I have tried everything, and thik it’s my computer. I accessed my user name on another workstation and I saw what I was looking for.
Has anyone had a problem or had anything like this??? Please help if you do, thanks