Question : Problem: Laptop wont Boot OS

Laptop will boot to bios,but wont load OS.I notice date and time are incorect.Is there a battery in this computer like in desktops .

Answer : Problem: Laptop wont Boot OS

Sounds like you will need a new BIOS / CMOS battery, replace like for like - there a lot of different types of these batterys ranging from chargeable cells to your standard watch battery type cells.

http://www.google.co.uk/search?hl=en&q=inspiron+4000+cmos+battery&meta=
quick search there - I couldnt realy recommend a site as Ive never had to buy a new CMOS battery myself - if you can, stick to a well known / popular site.

Just make sure the model numbers are identical, sometimes you can find a part that looks perfect and just a minute difference in the connecting plug - thats a show stopper.