Many years ago I had Cakewalk, but have not been working with it for ages. First I need to be able to access my old WRK files, then I need to be able to actually write the music as I do not have access to the instruments that I need or the equipment necessary. Does Sonar have that capability? Or is there a different program I need?

 
Not to sound cruel, but since you are on the Cakewalk site, why not take advantage of the site and read about Sonar and what it offers and then you can ask specific questions about certain features of the software.
 
Read more about Sonar first.  http://www.cakewalk.com/Products/SONAR
 

SONAR does a staff view where you can enter, and then print, standard notion; but I have always found it clunky to use.  It me SONAR functions much better if you enter the music via a keyboard rather than by hand.  I think, but I don't know, that Sibelius is better if you want to enter standard notion by hand.
 
Cakewalk does have a free demo, so you might give it a try and see if it does what you need.
 
Best of luck.

Not cruel, Jesse, just rude! It would not have taken you any longer to answer my question than to patronize me like that!
I have spent 3 hours on the website and combing the internet for information and have yet to get an answer.
Hope you enjoy your high horse!

Thank you, Jude, you kindly answered exactly what I needed to know. You are awesome!

Betttsmd,
 
I wasn't being on a high horse, I figured it would meet your needs by viewing more of the sight and reading what Sonar had to offer you.  There are different versions of Sonar, so based on how much involved you want to get with with Sonar again, you will need to read about what each version has to offer you.   That is why I prefaced the reply with, "Not trying to be cruel" first.   I provided you with the link to the information about Sonar and then said, "Ask specific questions about certain features of the software".   
 
It wasn't rude, it was informative.   I gave you a link to find out more about the newer Sonar and what features it now contains since you last used it. Then,  I invited you back for a discussion on the features of Sonar you may be interested in discussing.   I'm sorry you took that the wrong way.
 
I have to go now, I have my equestrian training class in 15 minutes.

All Sonar version can open wrk files. 
Bettsmd welcome to the forum. 
 
Jesse is a very good member and meant no rudeness. 

There are various ways to "play"  instruments in SONAR, recording is but one (audio or midi).  If you "notate" SONAR hasn't improved much since your days, or so I hear.  But midi, you can "paint or draw"  it in, step sequence it or put in in a Matrix cell and play it in sync with other midi loops or audio clips.  or play it in on a virtual keyboard which drives a soft synth like a physical keyboard.
 
SONAR includes various softsynths, and more and better choices the farther up the pay scale you go.  Rapture synth and Dimension Pro sample synth have been replaced by Rapture Pro (which includes all the samples and presets for both) but SONAR Pro, I believe, includes both those excellent synths.  Plus Addictive Drums and a bunch of older synths.  If you are making rock and pop or electronica SONAR is a good choice, even if you don't record.  If you are writing by hand classical or jazz, you might want to look at other hosts too.
 
@

PS, Jesse, as noted, is a good and helpful guy.  You just didn't really give us much to go on and I think he was hoping for more hints.

In case you might have missed it, here is a link to detailed comparison of the versions of Sonar : http://www.cakewalk.com/Products/SONAR/Versions#start . Note that for many items, hovering over the name of the item reveals additional information. If your you WRK file has more than 64 tracks or more than 8 bus tracks, you would probably want one of the versions "higher" than Sonar Artist. Otherwise, any of the versions would be a great place to resume working with Cakewalk functionality. It is worthwhile pointing out that the monthly development cycle has resulted in considerably more functionality than might be obvious just from the feature lists. The Reference Manual (included in the program folder when installing), Groove3 and other online training services, and these forums all provide excellent support for learning the program at whatever level you require.