How much memory can I reliably put in a Dimension 4300.

Currently have 512, but installed Win7 & need more.  I know there are a bunch of this same question floating around, but the most recent I could find was 2008. I don't even think they had 1GB DIMMS then. I know Dell published a max of (2) 256GB - (512 total) and Dell is not going to contradict that spec, even though it was published 11 or 12 years ago.  I sure don't think there have been any technological advances since then.

I need someone to respond who has actually succeeded with 1 or 2GB.  Must be reliable. Cash is REALLY tight, so I can't afford trial & error.

Been using an Inspiron 1525 that crashed & burned several days ago.  All settings & data were backed up. NO LOSS!  but I need to get something going.

I installed Win7, which seems to work ok, but  v-e-r-y  s-l-o-w.

ALSO:  If anyone has some used 1GB sticks with the following specs, you could save my life.

Architecture                 SDRAM PC133
Memory connectors     two
Memory capacities      64-, 128-, 256-, and 512-MB non-ECC or ECC SDRAM
Minimum memory       1 64 MB
Maximum memory      512 MB
Memory type               PC133 (non-ECC or ECC)