I startled using Lemedit on my Laptop and the white arrow that you move with the mouse is too slow making it hard to use. Is there a better one that works fast?
Too slow?
I personally hate laptop mouses, so what I would do is get a mouse input AND/OR find the Control panel and click on "mouse", then I click on the tab "Pointer options" and set the speed for the mouse. Just be warned: It's not tried and tested and I don't know if this works for LemEdit.

I remember, you're trying to get the levels you made from the PSP onto the computer, aren't you?
Yeah I think it's about time I remake those levels. The arrow moves fine when I'm not using LemEdit. I'll see if Lemmix works better.
Edit: I got Lemmix. Where do I go to make levels? I went to 'New Levels' and it's asking me to enter a code.
You got the "wrong" Lemmix. There is a "Lemmix" level editor, and then there are the so-called "LemmixPlayers" (aka "Lemmix Lemmings Clones") which are clones of DOS Lemmings, DOS ONML, etc. The latter (which you've apparently downloaded) can only be used to play the original game levels.
In other words, you want to download this:
Download Lemmix Level Editor latest alpha version.
You'll need to go to the website and read the installation instructions to better understand how to set up Lemmix. In particular, you'd also need to download the files for CustLemm, and edit LemmixStyles.ini to point to where you've put CustLemm.
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For the LemEdit slowness issue, you can try running it in
DOSBox, using Ctrl+F12 to speed up the emulation (change it so the window title bar has "Cycles" reading something like 12000-20000). It'll still feel a little slow but should work a lot better than at default emulation speed.
Where do I download CustLemm and Lemmix.exe? what do I do about LemmixStyles.ini? It saids there's something I need to edit on that but I don't know where.
I responded to the PM you sent about it, that should work. Oh yeah, I'd say Lemmix is a great editor, but it can be a pain to set up. LemEdit is usable, and it doesn't take as much work to set up. However, its interface is not as nice.
EDIT: If you can hold off until up to this Sunday, I can send you a prefectly working Lemmix folder. I probably can beforehand, as well. You may need to edit some pieces of LemmixStyles.ini if I do this, but most of it - you know what, here. The just of it is here, but some editing may be required (namely, the directories). If the zip won't decompress properly, I need to know so I can file a bug report - I haven't tried unzipping a zip archive I made in Linux in Windows. There shouldn't be a problem, though.