Windows 7 - Folders with random numbers and letters. Changing Computer name?

Hello everyone, I have had several folders with random numbers and letters on my computer for quite some time now. They're located in the C:\(Username)\App Data\Local folder. There's a few folders that have {FFF9808001018839} or something similar to that. When I click on them, they don't have anything in it. Some have another folder or two, but there's nothing in them either. I don't why they're on here or I should delete them or not.

I'd like to know what kind of folders are safe to have and what are not. I'm worried I may delete something that's important to my system. Before I delete anything, I do research online and I don't delete it unless I'm 100% sure that I have to. Some of things on here, may be from downloading music, programs, and videos. But none of them are on my computer any longer and I'm afraid there could be some things that shouldn't be on here.
(My computer is always running fine and there not affecting anything. It's just annoying to see all of them there and I would like to have my computer as clean as I could have it).

The other question or issue I have is that my computer seems to have the stock name on it. Three numbers and two letters. For instance my documents and files that I create are saved under C:\454HX\Documents\English Essay

That's not what it is of course, but it's similar. It's really annoying to have because it makes me feel like it's not personal. Yes, I know to go the Control Panel and Username and Account Settings. I have changed it a few times already, but the "454HX" still shows up. I don't know where to go for this.

Any help or ideas is greatly appreciated! If you need additional information, let me know. And sorry if this isn't in the right category. I wasn't sure where to put this.

The folders you are finding in the AppData folder are just temporary folders used for things such as installations. It won't do you any harm to delete 'em, obviously because they are empty, but it also won't harm you to just leave them. If you are worried, just make sure you have an Anti-Virus with Real-time scanning. Do a full scan with Malwarebytes too, its more effective than other solutions.

I do not understand your second problem much. Are you trying to say that your User account folder in C:/Users/ has a different name than your User name? And does your real proper User Name show up in the Control Panel?

Slasher

Thanks! I will delete the folders, however my C:/Users/ has a very odd name such as 435DX
It's really annoying, but in the Control Panel it says that my account screen name is Timmy. Which I know it is, but all my documents have the 435DX name after "user." I don't know what to do about that, I showed my father and he doesn't know either.

It's been like this ever since the first day I brought the computer home. Other than that, everything runs perfectly fine and there's not an issue with anything else. And it doesn't affect anything, but it annoys me.

Run sfc /scannow from the command prompt. Change the name from Timmy to something else. Then change it back to Timmy. Did the User name on the folder change? Also, what is the name of the Computer itself? You can find this by going into System into the Control Panel.

Slasher