Whats happened to my laptop!?

Help, my dell insprion 1545 has crashed , its only 10 months old, it started by me turning it on as normal , and then it was slow as it took 20 mins to fully load up, i restarted it and then it went back to default settings as if it was new!, i restarted it again! back to normal only slow left it for a further 25 mins to load and restarted it again! now all it says is windows in unable to boot!, was purchased from tesco direct last year!, it has plenty of memory and has worked up until today! id like to know how to fix it as all it says is reinstall windows 7 again but i had no disk with the laptop! Im more worried about losing all of my files ie : coursework, photos ect! help as if i cant get the files back then i have no reason to keep this awful thing!