usb stick says it needs formatting but there are files on it

Don't click format, that's the one thing. Try it in a different port and on a different computer first, sometimes it's just a flaky read. If it still asks, open Disk Management and look at how it shows up: partition there but marked RAW means the file table is damaged and the data is usually all still on it. TestDisk, free, can often repair the partition table in place, and PhotoRec from the same download pulls files off regardless of the file system. Copy everything it recovers onto the laptop, THEN format the stick, and stop trusting it with the only copy of anything. Do the recovery before anything that writes to the stick, chkdsk included.