In a word: No. But.. what was the loop doing and what language was it written in? If it was renaming, moving, deleting files, yes of course it could crash the system, don't be too surprised if the system won't reboot! If he was trying his hand at systems programming in assembler, then anything could happen and its very easy to ah heck something critical!
However, there are a few fixes, firstly if it is a laptop, infinite loops can screw the sleep and hibernate modes, take out the battery for several minutes and try and reboot it. If it has a reset, carefully reset with a paperclip.If that fails, go into BIOS (boot with Delete, F2 or ESC) and check every entry or reset defaults. If that doesn't fix it, boot PC from USB drive or supplied windows disc, select safe mode and if you know what you are looking for should be easy to fix. Last option, reinstall windows, select the option to preserve data.
If you want to get into programming, you must use XP, Windows 7 or Win 10, Vista has an awfully bad reputation for not protecting itself!