Dell Vostro 1700 reports more RAM than installed

[TKCPrime]

So I have a Dell Vostro 1700. I bought it about 8 years ago. It ain't young, but it has performed well until it started this wierd behaviour. It shows 3GB of DDR2 RAM in windows and in the BIOS too(A07) no idea why. I checked the actual memory stick. it states it is 1 GB. I'm at a loss here fellas. It is sluggish. It was sluggish in windows 7 for a few years now. The system just recently undervent an upgrade to windows 10 too and altough it performs faster than expected it is still slow at times. Mind you I rarely use this machine as I gifted it to my parents, the windows 10 upgrade was just an experiment/happy accident.

So my question is: What the holy hardware conundrum Batman?

Any input would be appreciated.

 

[TKCPrime]

AAAAAAAH I'm soooooo stupid. That was the extension DIMM slot. The pre installed RAM is somewhere else in the chassis. I'm sucha doofus.