Better have a look in the motherboard manual (which you probably didn't get, so contact Dell tech support) what this little light is trying to tell you.
I recently had exactly the same problem on my 4 year old custom build PC. It turned out to have 4 red or green ligths, and any combination meant an error in a certain phase of the boot process. However, I forgot to look in the manual myself, brought it to a repair shop and ended up with a new motherboard/CPU/memory/power supply combination. To finish it off I had a new videocard installed, and a DVD-reader, so now I have a practically new computer in the old case, for practically the same price as a totally new one. I sold my old memory sticks (192 Mb SDRAM) in less than a day via Internet, but that didn't make up for the costs at all.
I had hoped that I wouldn't have to do a fresh install of Windows, but I had to do so to get the sound on my new motherboard working.
Depending on your needs and the exact diagnosis, the best thing to do might be to salvage things still useful and throw away most of that old PC.
Hi, I got this pc from a friend he say it did not work, I plug it in and nothing, I checked the conections of the case to the mobo, and they seem to be correct, I think the PSU works because there is a ligth on the mobo, that is the only think that works, a little ligth on the mobo.
The pc is a Dell
celeron 600 mhz
192 mb of ram
any idea, what could be wrong?