Sorry for my silly question, because I am just a beginner of home

My old desktop is originally equipped with an old 10 MBps NIC (IP set
to, it is networked with my newer Laptop (with 10/100 MBps
NIC, with IP set to Linked-up by cross-over RJ45 Twist
Pair Cable.

This home network has been working fine for several years for simple
file sharing & Internert sharing using Win 98SE's ICS feature.

Recently, my friend give me an old 10/100 MBps NIC, so I install it
onto my old desktop with the view to establish a quicker 100 MBps link
with my Laptop for quiker file transfer & internet browsing.

I install that 10/100 MBps NIC onto my desktop & set its IP to, with correct Workgroup Domain Name & Computer
Identification name. Very simple works

I switch over the RJ45 Cable from the 10MBps NIC into that newly
installed Desktop's 2nd NIC (10/100 MBps). Re-start both Desktop &
Laptop, but unfortunately, cannot establish the link. Repeated
serveral times, still cannot linkup.

I switch back to the original 10 MBps NIC & re-startup, it works
perfect fine again.

My conclusion is that the NIC or its software must has memorized some
old settings.

I seek advice from my friend (claims to be Network Expert), he said I
need to RELEASE both NIC's IP addresses (i.e. Clear away those
original settings that it has memorized)

What is the meaning of "RELEASE IP" for NIC ??? & How to do it? so
that I can upgrade my networking link between my desktop & laptop from
original 10MBps to 100MBps.

Thanks in advance