I have a really old Mesh P.C. which did sucessfully install and run XP (so it should I hope be capable of running Lubuntu) was Windows 95 before !. I decided to try Lubuntu and burned a live disc. I believe it has installed O.K. but when I boot from HD I get "grub rescue" after "unknown file system". I then tried the boot-repair as suggested and it did a load of stuff. But I still have the same problem. Here is the url for the boot info summary created after boot repair ran. http://pasteubuntu.com/5758560/
Due to the small HD I got the installer to ditch XP as it was needing to be activated and I lost the code.
I suspect this has fixed the boot part but for some reason I just cannot get it started ! Maybe a BIOS setting which needs to be changed to get the correct file system? Perhaps it is still set for Windows or something? I have no experience of LINUX and very little familiarity of changing BIOS settings.