If there are no other problems, and you are having trouble with the real-time clock, and also given that it is 3 years old or so, then all signs kind of point to your having a battery (for the real-time clock - again, it's not the bigger exterior or removable rechargeable battery to power the whole laptop, but a small battery inside it) that was not quite perfect from the factory, and so has failed in somewhat less than the usual roughly-4-or-5 years' time.
For the XPS M1330 laptop model #, the battery spec.s are ... not findable without your Service Tag (string of numbers and letters on your laptop's label, on the underside, which are individual to Dells the way the model # XXXXX't individual...), even if it's findable at all.
And Dell unlike some doesn't have a Service Center Finder, so I can't suggest where to take your laptop to have it serviced / real-time clock battery replaced [obviously, wherever you take it, don't include the rechargeable power battery with it, in case some numbskull decides to replace that - quite a pricier item, as a part!]
However, eBay has information, and something to offer, on this score:http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=110578116989&rvr_id=131677291857&crlp=1_263602_263622&UA=WXF%3F&GUID=6d10b51012a0a06456309600fffe53b7&itemid=110578116989&ff4=263602_263622
(actually these are the same item by the same seller - but the latter of the two listings ends August 30th, sooner than the other.)
Your RTC (Real Time Clock) battery is evidently a 3 V lithium disc type, in a small rubber case with two leads coming off it.
Scroll down on either of those pages to see info on it (eBay seller info is most usually accurate. They want to sell the right thing to the right person and not have it returned etc.)
If you want to try getting that battery and replacing it yourself, that can be done if you're careful, and there are actually instructions online, with pictures, for your model #:http://ahwee.com/how-to-disassemble-laptop-dell-xps-m1330
which are good for your purposes except for a few points:
A. don't go too far, this disassembly is for just general taking-apart purposes, not specifically for the small battery replacement. You don't want to go farther than Step 1 (Remove fan), sub-step 4 ("You can see your RAMs and the fan connected to the heat sink.") At that point, illustrated here:
...with the cover over this area removed (but nothing else! you don't need to remove anything else to get this far!), you can see the discoid battery, in its black cover, at the point of the arrow on the left. It has a label on it too, over the black cover.
To get the old battery out, you go to about under the base of the arrow, where its two wires lead, and you unplug the connector at the end of the two wires, from the board its plugged into - hopefully without having to remove anything else to get at it, and maybe using needlenose pliers or tweezers to remove it (-caution: don't pull the wires out of the connector individually, you have to get the connector off anyway, to put the new one in properly.)
Then just put the replacement in the same spot, plug the replacement's connector in similarly (-caution: remember it can't go on one way, to make sure the battery polarity is right, so try to plug it in the right way and it will work out.)
Or take it to a local laptop repair shop that you can trust (without including its big power battery - they don't need that to do the repair!)
If this helps with the problem and answers your question, then please click once on Accept for my Answer.
(Only then will I be paid, by deduction of my share from the funds already deposited by you with JustAnswer. Thanks.)
- Favorable feedback is appreciated.