upgrading a WIFI adaptercard for a INSPIRON 1545

You may want to open up your system to confirm, but from what I tell, that system uses a half-height mini-PCIe slot for WiFi, and the Dell Wireless 1397 uses 2 antennas.  In that case, you can do MUCH better than the replacement cards you're looking at, since none of those support 802.11ac.  I tend to prefer Intel WiFI cards, and the best WiFI card Intel made in that slot type before moving on to the newer M.2 type (which you can't use) is the Intel Wireless-AC 7260.  To make sure you get the correct card version, get the Intel 7260HMW -- do not get the 7260NGW.  Also make sure that you buy a Wireless-AC 7260, because Intel also made a Wireless-N 7260 that only supports 802.11n, and not 802.11ac.  I have no idea why Intel used the same model number for cards with completely different feature sets, but there you go.  You can find the right card on Amazon for about $30.

In terms of compatibility, Dell does not use a WiFi "whitelist" or engage in hardware shenanigans like some other vendors in order to restrict the WiFi cards you can use in their systems, so you won't encounter any issues like that.  The only time I've run into compatibility issues on a Dell system when upgrading WiFi was on an Inspiron system that used an NVIDIA motherboard chipset -- it wouldn't accept any of the 3 Intel WiFi cards I tried, and I had to resort to a Dell/Broadcom card instead.  So it is technically possible you will run into issues, but it is very unlikely.  Unfortunately given how old the Inspiron 1545 is relative to the Intel 7260, you won't find a formal compatibility guarantee, although I guess you might find someone who's performed this upgrade before.  But given how inexpensive these cards are and how likely it is to work, I would start with the 7260, and worst case you can return it and get something older instead if it doesn't work.

In terms of installing it, if you've never installed a WiFi card before, you insert it initially at a 45-degee angle relative to the slot, then press the top edge down so the card lies flat, and then screw it down.  One tip: If you have enough slack on the antennas, I would recommend connecting those before you install the card because that way you can "pinch" them into position by placing your index finger on the underside of the card directly behind the antenna connector and use your thumb to press them on.  Then after installing the card, make sure the antennas are still securely fastened because a loose antenna connection will severely degrade your WiFi performance.

Lastly, you'll probably want to download (but not install) the drivers for your new WiFi card before you remove the old one, because otherwise if the Windows version you're running doesn't natively support the new card, you won't have any WiFi until you supply a driver, which can make it a bit more challenging to get on the Internet to get the driver.

after reading this post I purchased the Intel 7260.HMW Dual Band Wireless-AC 7260 Network Adapter PCI Express Half Mini Card 802.11 b/a/g/n/ac.

I have the Inspiron 1545 as well. But after installing the OS recognizes the bluetooth but not the wifi. In device manager it says unrecognized card. I downloaded the most recent driver pak from Intel but when I try to install it errors out saying more recent driver already installed.

Can anyone help?

Pinkstonm: did you ever get it to work?  I borrowed my mother's (unused) 1545 to give to my son for distance learning and am considering replacing the wifi card for better streaming speeds but also to get Bluetooth for his airpods.  I have upgraded this machine to Win10 and other than the poor wifi speeds it seems to run well enough for now.  Thanks!

I just installed this card into my Inspiron 1545 and it seems to be working fine.  I had the issue of Windows not noticing the WiFi receiver was there at all, while it did see the Bluetooth.  I had forgotten I had disabled internal wireless in the BIOS settings because I was using a cheap Wireless-N USB WiFi adapter (itself an "upgrade" from the original internal Wireless-G card).  Enabling that again did it for me.

I upgraded the adapter card because I was experiencing too much interference on the 2.4Ghz band from my other office equipment. I'll have 5Ghz for my LAN and Internet access now.  The Bluetooth still operates on 2.4Ghz, though, so I won't be surprised if I have interference issues with that.

@jphughan​ THANK YOU! Today (January 2024) they are running about $16.