Inspiron 1545 CPU upgrade, works fine but Windows and BIOS still show old processor- fix?

I got my sister a new WD Scorpio Black hard drive for Christmas (along with a 1TB Seagate Portable Expansion Drive) for her Inspiron 1545. The original hard drive actually crashed just a few hours after I finished backing up over 100GB of photos off of it, so I'm very glad that I did it sooner rather than later!

While I was upgrading the hard drive, I decided to make a few other upgrades to improve performance. My beloved but recently deceased Latitude E6400 had a faster processor, much better wireless card and the Bluetooth module and they were all compatible.

The 1545 had a 2.0GHz Core 2 Duo T6400 processor and I replaced it with a 2.4GHz Core 2 Duo P8600. They're both from the same generation (Penryn), but in addition to a 0.4GHz faster clock speed, the P8600 also has 3mb vs 2mb of L2 cache and several features not included on the T-series processors. It also has a 25W TDP vs 35W for the T-series, which should (could) translate into more battery life and lower operating temps.

When powerd up the 1545 with the new P8600 installed, it booted to the Windows Desktop without the slightest hitch. The only problem is that the laptop still shows that it has the T6400. When I select Control Panel, then System, it shows the T6400 stil installed. The same is true in Device Manager under Processors as well as in the BIOS setup.

I have installed all Dell and Windows updates applicable to the model, clicked on the Processor in Device Manager and selected Uninstall and rebooted with no success. I also upgraded to the laest BIOS version (14). What else can I do get the system information to update and show the correct processor???

Help will be much appreciated! I'd love to get this thing off my desk and back to her ASAP. The discrepancy in CPU model doesn't seem to be hurting performance, but it just drives me crazy that it's not correct!

 

An update of sorts- As I mentioned above, I installed a new Western Digital Scorpio Black (500GB 7200rpm) hard drive. After it was installed, I realized that it was showing as NOT activated even though I entered the Product Key when it was requested.

I was using the final license from a 3-user Windows 7 upgrade disc that I bought several years ago. I used it to upgrade from Vista on my Latitude E6400 and Inspiron 530 desktop, so I had one license remaining. BUT because I was using an 'Upgrade' disc and there wasn't a previous version of Windows on the hard drive, it wouldn't accept the producy key and activate it!

I had already installed all of her freakin' programs and copied about 50GB of photos back over from the external hard drive. After 4-5 hours or work, I went to the Windows website and discovered that a clean-install on a new drive required a few different selections in setting up the installation process! So I had to start over from scratch, select the 'Custom/Advanced' installation option instead of the much simpler default....and now I get to spend my Saturday and/or Sunday reinstalling everything again.....

Since the previous clean install didn't cause it to recognize the new processor model number, I doubt this reinstall will either. As I said, it works fine, it's just displaying the old T6400 info and that drives me insane! Someone has to know how to fix that......

Thanks again!

 

You used an upgrade disc to do a fresh install right? There's a simple registry edit you can do to activate Windows. Use solution 2:
Clean Install Windows 7 with Upgrade Media | Windows 7 content from Paul Thurrott's SuperSite for Windows