I just got a new computer and when setting up LR my Lbrary will not fully load. What can I do?
What do you mean when you say the LR library won't fully load? Does the catalog open correctly but you are missing images? If so, check the folder to see if there any question marks there meaning LR doesn't know where those images are so you have to right click on the folder (try the topmost folder first) and then locate the photos.
When you moved the photos and catalog to the new computer, did you put the photos in the exact same folder structure as on the old computer? If not, that's why LR doesn't know where the photos are.
If it is something else, please describe in more detail.
I would like to help you but you need to describe the problem in more detail. I can speculate what you mean when you say 'only part of it' appears but that isn't productive for either of us.
Please answer the questions I asked in my previous reply and, importantly, describe in detail what you think the problem is. Are you not seeing images? not seeing folders? or is it something else altogether?
What software are you talking about? Lightroom (Lr icon) or Lightroom Classic (LrC icon)? Or something else? What version NUMBER?
What do you mean by "will not fully load"? Describe exactly what happens. Show us a screen capture. Include the screen capture in your reply by clicking on the "Insert Photos" icon. Do NOT attach files.
Describe, step-by-step, leaving nothing out, how you moved everything (catalog and photos) to the new computer?
It sounds like you have (accidentally?) opened the wrong catalog file.
Go to File->Open Recent and select each catalog file shown there until the you find the one you want. If that doesn't work have your operating system do a search for all files whose names end with .LRCAT (not .ircat), and double-click on each one to open them.
This "The File could not be found" means what it says. Often in cases like this it is because the photos are in a slightly different location on the new computer. For example, they are on a drive which has a different letter.
You can fix the problem photo-by-photo, but fixing the folders is the best first step.
First look at the Folders panel and see if any top level folders have question marks - ie are missing. Note where LR thinks they are. Then use Explorer to look around your computer and drives to see where these folders now are. You can then right click the folders in LR and use Find Missing Folders to tell LR where the folders are.
Does this resolve the problem?
Do you have full access to the external drive via the Windows Explorer?
Is the external drive connected to ther new PC with the same drive letter as on the old PC? If njot please change the drive letter to that is been using on the old PC.
Here you'll find infos how to do drive letter changing: Change a drive letter | Microsoft Docs
Maybe that will help.