Online translation of your question:
Last week I installed Lubuntu 20.04 on a PC with 4Gb Ram and 512Gb disk. That PC with Windows 7 worked fine but I made the mistake of installing Lubuntu, which had already given me inexplicable freezing problems on my laptop. This problem has been around for months on the Lubintu 20.4 forums. Is there any solution? or can someone recommend me a more stable distro that doesn’t consume too many resources? Thanks!!
You didn’t state which ISO you used to install; which provides details on the kernel stack you’ve opted to use. If your machine is getting old, the GA stack being older tends to be perform better for some devices, but newer devices tend to perform better using the newer HWE stack; so you could switch from your unstated current stack to the other choice Ubuntu LTS users have available.
For details on the stack choices, please refer to
(if you installed with 20.04.2 media and are thus using the HWE kernel, look at the first link & search for “*To downgrade from HWE/OEM to GA kernel: *”. Lubuntu 20.04 & 20.04.1 media installs defaulted to the GA kernel)
The possibly more likely question is have you enabled swap?
On a system with only 4GB I’d recommend having swap enabled, as, whilst it won’t freeze a laptop, it’ll appear to impact your system that way when your system is lacking ram - see How to create a swapfile in Lubuntu 20.04 and 20.10
All distros are built from the same source code, so one is generally not more stable than others, it’s more specific hardware tends to prefer a specific version of packages/software (esp. if hardware related; it’ll be the kernel version). 20.04 tells you it’s the 2020-April release of Lubuntu which tells you the age of the software; use that as a clue to compare with the age of components in your unstated box.
Sorry I don’t speak en español, so you’ll need to wait for a non-english reply