When you say not recognized, you mean it is not given a drive letter?
If that's the case, then open up Disk Management and scroll down through the "drives" to see if it is listed near the bottom. If it is, then see if it will let you assign a drive letter. If that work, you should be OK.
If you don't see it in Disk Management, then the next time you boot, do so with the drive connected, go into the BIOS setup screens, and see if the BIOS sees the drive. If that doesn't see it, then there's no way to mount it to get the files off.
However, if the BIOS does see it, then you can at least try accessing it following the info below ...
Since your data was on a Windows partition, based on my experience at doing
this successfully, my suggestions are the following:
[NOTE: If your PC has a working copy of MS Windows on it, skip to step 4]
1) Connect your drive to the PC.
2) Download and install the trial version of RecoverMyFiles from Runtime
Software in MS Windows.
3) Right-click the RecoverMyFiles shortcut and select "Run as
Administrator"
4) Select the option to Recover a Drive
5) You will get a list of drives, scroll down to find the one for your
drive.
If it's shown in the list, then continue; else, you're done and won't be
able to recover the files...
6) Select Automatic Driver recovery, press Start button
7) It will run for a while but when done, will show a directory tree in the
left pane. Do NOT interrupt it.
8) When done, browse the folders in the directory tree -- and be SURE to
check the filesizes of the files you want to recover. If the filesize is
zero, the file is trashed and you will NOT be able to recover it.
If the files look OK, you will need to contact Runtime Software to purchase
a license for the recovery. You won't have to reinstall the app; instead,
they will email you an activation code which you can use to turn on the
recovery feature.
According to their website, the "standard" version of the app is $70 USD.
They also have a Pro version for $99 dollars, but if you go to the website
below, you can compare the features and (at least for me) the extra cost
wasn't worth it:
Recover My Files: Purchase GetDatas Recover My Files data recovery software
Your data ... your money ... your choice.