And, now, when I set it to the right time manually, it has started loosing minutes - going slow. It looses an average of 3 minutes per 30 minutes or so, just at 1st glance/guess.
This sounds like some kind of NTP client is running on your computer. Personally, I'd use msconfig to disable all startup programs (except your anti-virus, of course) and restart. You will get a message about the computer starting in Selective-Startup Mode; this is a good thing. Try changing the time and check to see if it is still drifting/resetting to an incorrect time.
If the problem goes away with all start-up apps disabled then we know that one of them is the culprit. If you still have the problem, then it is something more "fun" (gods, but I hope not). If it goes away with everything disabled, then you can start enabling programs either individually, or in small groups, until the problem comes back. When it returns, then there is a very good chance that one of the apps you just re-enabled is the cause.
I had this problem when I first got my Inspiron B130. Try this.
Make a copy of files and folders you can't afford to lose. I haven't lost any doing this procedure but just in case it's a good policy to do so.
Insert the Windows Operating disk.
Restart the computer.
Press any key to boot from CD.
Do the agreement.
When finished, your System will be back to the way it was when you purchased the computer. You'll need to get your Windows Updates again and just check and make sure your virus protection is running and up to date. Your files and folders should remain untouched if your computer is a Dell. Doesn't work well with other brand names. Usually with the other name brands it wipes everything totally.
This was the only way I could get my clock to sync again. sfc/ scannow did NOT work.
Original poster, If you have solved your problem, can you please mark the correct thread(s) with your solution. Thanks
Welcome to Dell Community!
#MicrosoftMVP - Windows Expert-Consumer April 1, 2012 to March 31, 2015