The reason you can't find any upgrades for your 4300s BIOS is because there are no upgrades available.

Steve

what do you mean? there just cant be NO updates for my particular bios... is there any website that has it?

Dell only updates the BIOS if it finds problems or deems it necessary to support new or different types of hardware. Furthermore, Dell usually does not continue to release BIOS updates after it stops selling the particular model. If Dell does release a new version of the BIOS, it can be found on the support web site. Searching for BIOS updates for the 4300s, returns no hits, indicating that an upgrade is not available. Thus, unless they have released updates and by some mistake have not posted them on the web site, it appears that no updates are available. If you want to find out if it is just a mistake on the web site, either call Dell Tech Support directly, or post on the Dell Website Help forum on Dell Talk (accessed only by using the Jump to Conference drop down box at the upper right of the Dell Talk window).

Steve

I am trying to find a BIOS update higher than A02 as well for the 4300s. Supposedly, the motherboard on the 4300s supports up to 1.90GHz processors and CPUs with 512KB L2 cache. The only intel cpu with 512KB L2 cache is the 1.8AGHz cpu. I have tried 2 different 1.8AGHz cpus and the BIOS won't properly recognize them and claims that they are 00 MHz processors but does recognize that they have 512KB L2 cache and if it will actually boot up all the way into WINXP Home it XP recognizes the correct speed etc. but the computer will randomly freeze and crash. I'd say that is probably something that might be BIOS related. Anyone got any ideas? Thanks in advance. 

Rootjedi, although the Dell File Library does not contain any BIOS upgrades for the 4300s model, there have been past reports here indicating that the 4300s uses the same BIOS as the 4300 system.  You can click here for the A06 BIOS version for the 4300 model which is the latest and last release for that system.  This download will create a bootable BIOS upgrade floppy disk.  As the disk is being created the program indicates that the upgrade is for both the 4300 and 4300s models.  Although it is unknown whether this upgrade will support the processors you are trying, this best you can do is try the BIOS update and see.  Seldom if never does Dell list in their BIOS histories the specific processors supported by an update.  In the case of the 4300/4300s BIOS version, there is several references to the BIOS updates "adding support for newer processors."