There are a variety of tools that allow reading PAX and it's cousin tar archives from tape. One option is the Microsoft Unix tools. I haven't used them on Windows 7 but there is a version called "Subsystem for UNIX-based applications" that is supported on Windows 7 and should be pretty close to the server versions. It doesn't work with the home versions though:
https://www.microsoft.com/en-us/download/details.aspx?id=2391
Here is a link to a Microsoft article about reading PAX archives with the Services for Unix tools that used to be offered for servers. The functionality in the newer tools is probably pretty similar.
https://technet.microsoft.com/en-us/library/bb463200.aspx
It is likely that the Cygwin version of Pax could also read from tape. http://cygwin.com
I work for HPE
There may be some GUI tools but I haven't used any for reading archives like this from tape. Command line tools aren't too bad. If you search a bit there are probably a bunch of examples for pax command lines to read tapes.
I think Cygwin is a real pain to install but it usually works pretty well once it is installed. If you install from the internet and just go with the defaults it doesn't put on pax. The defaults are a pretty good start though. Run the installer again and when it gets to the screen with all the available software just type 'pax' in the search box and wait for a second then it will show up with 'Archive - Default' and if you expand that it will show 'pax: Portable Archive Interchange', probably with the 'New' column set to 'Skip'. If you click on the 'Skip' it should change to 'New', press 'Next' and it will install pax.
Once you have pax installed if you only have 1 tape drive connected you should be able to load a tape into the drive, open the cygwin command terminal, and type 'pax -v -f /dev/nst0' to find out if the tape is a pax archive. You can type 'man pax' for a manual page.
I work for HPE
You say "i ran 'pax -v -f /dev/snf0'"
The value following "/dev/" is the device that you are trying to access. Is there some reason you picked the device "snf0" instead of the "nst0" device I recommended?
Pax is reporting that there is no such file as /dev/snf0. If there is a tape drive with a driver installed the /dev/nst0 should always be there and should correspond to the Windows device TAPE0.
The command format I suggested should report what is on the tape if it detects that the tape is pax format once you direct that command to the right device.
I work for HPE
I agree - looks like it isn't pax but you are making progress.
Here is another command you can try with cygwin:
dd if=/dev/nst0 of=junk.bin bs=1M count=1
>> Be Careful << this command can write to tape if you get it wrong. The command line above is asking the 'dd' command to read from infile "if" names /dev/nst0 and send to outfile named "junk.bin" with a blocksize of 1MB and read a count of 1 record. As long as the outfile option "of" points to somewhere in your filesystem where you want the file created you are safe.
If the command reports informatin including "0+1 records in" then it means it successfully read the first block off of the tape into the file which in this case I named "junk.bin" - if you load that into a binary file viewer it may have information about waht application wrote the tape. Many applications write ASCII text into that first block identifying the application that wrote the tape.
I work for HPE