I need a manual

Anonymous,
You can click the link below to download the online manual for the Dimension 5100 system. The manual provides information for removing/replacing parts within your computer.
Dimension 5100 Online Service Manual
http://dell.to/1vEC70f
Thank You,
Dell-Jesse L
Dell Social Media and Communities
#iwork4dell

MS Fixit has many user input solutions. I used the install awhile back, but the new site has way more features.

http://support.microsoft.com/fixit/

power supply installation for dell dimension 5100 is not that much hard, what you need to do is to remove the old power supply and unplug the cable from the mother board

You can contact The Best Pc Doctor team for any technical help. Their contact details are given below.
www.thebestpcdoctor.com
877 407 9229(Toll free)

you can download from http://support.dell.com/support/downloads/driverslist.aspx?c=us&l=en&s=gen&ServiceTag=&SystemID=DIMENSION%205100&os=WW1&osl=en&catid=&impid=

you are going to click on Chipset Tab.

You can do it two ways:
1) call Dell and order a recovery CD--their contact info is on dell.com
or
2) use a regular Windows CD and install the system using the product number affixed to the case. Then go to Dell at support.dell.com to download the needed drivers.

The green light just means it is plugged in and getting power.Try pulling the plug, the green light will go out. If you can remove the battery out of the motherboard, "it looks like a quarter", leaveit out for a couple minutes and out it in 'The same way it was" make sure you "look" at it before removing it, it has a little release thatenables it to lock in, or pop out. plug it in and give it a start. It may just be the settings got corrupted, that little battery saves the start settings, once it starts, we can go into the bios if any settings need changing, I'll keep an eye on this post, good luck

I would try asking dell.go to www.dell.com lala linda

I'd recommend purchasing a new power supply.

Your Dell Dimension 5100 comes stock with a 305W power supply. This is a bare-minimum wattage that will only handle what they ship on the system & not much more. You're better off upgrading the power supply with a compatible after-market model.

You can go to a PC parts store in your area and take your chances...but they're usually more expensive then Internet sources (they've got to pay for their brick-n-mortar store overhead).

Here's a link for a very inexpensive replacement 400W power supply for your Dell Dimension 5100:

http://www.affordablesurplus.com/dell-5100-5150-power-supply.asp

This particular site offers $8 Flat-rate shipping & a 1 year warranty. Your power supply is only $49.99 - you might be able to find it cheaper elsewhere, but that's the best I could find with a quick Google search.

If my answer helped you, please provide feedback :-)

Good luck!

you can get it  microsoft home site or from any software vendor