I recently dual booted my laptop of 4GB RAM into Windows and Debian. Since then I have observed that it has slowed down considerably. Hence I wish to expand its RAM. My laptop has extra slots alright, but the only concern is that whether the grub boot-loader as well as the windows boot manager will recognize the increased RAM size and boot properly. I have made a lot of modifications to my Linux so I don’t want to make it crash and re-install…
After you install the RAM, go into your system’s firmware (BIOS or UEFI) and see if the installed memory size matches what you expect.
Generally if the system firmware on boot is seeing the additional RAM, everything else will. Boot loaders haven’t had issues with RAM size since the 90’s or possibly around the time things were moving from 32-bit to 64-bit support.
Unless your Linux modifications involve something extremely weird like carving out specific RAM addresses for MTD devices, no need to worry. Increased RAM size might also cause Linux boot problems on some weird ARM based platforms, necessitating some kernel command line args, but you shouldn’t have trouble on a standard x86-based desktop or laptop unless the RAM is defective.