380 what, what case is it.? case size tells what mobo is really there, MT,DT< USS, (of 3 sold)?????

what w7 install media is it?,  Microsoft has no support media  now, and w7 goes dead jan 2020; (zero support)w

w7 , 32 bit or 64bit? 

the driver for this PC is on your support page.

of the internet is dead how can that usb/ethernet dongle work (it cant) (it came with zero driver disks, sure)

do hard reset on any PC with any I/O acting up (latchup happens and is normal for surges)

next is that old 10 year old 380 needs  new RTC battery now. below 2.9vdc it is bad, and dying fast.

my 380 runs w10 -64bit,  (ask how) as does ethernet as you fresh install w10. (works out the gate)<<< installed.

The MS  install works with ethernet connected, using w10,1903, or up, w10.

E6300 CPU newest stepping CPU runs w10-64bit (have proof)  the Q9650 quad CPU runs too.

dell does not support w10 here, but it does work , via , ethernert connected at fresh W10 install. PnP works.

not saying sound works, just all else.  I run sound DACs anyway so never worry complex issues with sound and and OS verisons, (or use  a sound card  or use uSB sound  if problems arise)

the drivers for w7 are here,  all of them,  (do not use others, just  DELL, or MS PnP or intel) (mobo answer)

DRVR_WIN_R257446.EXE

the correct one for Ehternet would be the one marked CHIPSET. intel G41 is what is there.

see ICH7 below, this is where ethernet connects. and is the slow version!, an Ethernet PCIe card Gigalan up grade would be far better. if you home is gigabit to the curb now.

before installing any OS we test the HDD first for Smart errors, if yes, it is NO GOOD , trash the HDD.

do the long reset

put in a new Coin cell if 10 years old,

try w10, buy lic. for $5 of ebay (OEM versions are cheap) and run w10, 

buy gigalan PCI-e card. ethernet, (w7 is NO GOOD now, avoid it)