folder protection

Clarifications

First we would need to know what you where actually using. Then you would have needed to save he encryption key/s. If you can not answer yes to both of these questions then your data is most likely gone to Silicon Heaven.

Now if you where using Windows Encryption system M$ best advice will be to find a Good Hacker to break the encryption on the software to recover your data. If you have someone you can try so much the better. You can also approach Data Recovery Houses and ask them for a Guesstimate on the cost of recovering your data that has become trash because you failed to save the encryption key/s. Or if you have friends in the right place the Feds are able to decrypt encrypted data so they are capable of doing this but unless there is some major Criminal or Terrorist reason they are unlikely to be willing to do it for you.

Grab the data off your backup's and recover from there it's far cheaper in the short term. If you don't have a valid Backup your only alternative is to approach a friend that works for the federal Computer Crimes Division or ask a Data Recovery House to recover your data by cracking your encryption. But you'll need to be able to tell them what program was used to encrypt the data or it will be far more expensive for you to get the data recovered.

Col

Do you still have the original folder protection software? Good policy to keep the installers.
If you re-install this software does that decrypt the protected folder?
The key here is that software uses its own language to encrypt.
You could try using windowsxp
To decrypt a file or folder
Open Windows Explorer
Right-click the encrypted file or folder, and then click Properties.
On the General tab, click Advanced.
Clear the Encrypt contents to secure data check box.
Note
To open Windows Explorer, click Start, point to All Programs, point to Accessories, and then click Windows Explorer.
When you decrypt a folder, you are asked if you want all files and subfolders within the folder to be decrypted as well. If you choose to decrypt the folder only, the encrypted files and folders within the decrypted folder remain encrypted. However, new files and folder that you create within the decrypted folder will not be automatically encrypted.
This is just a stab in the dark idea you coudl try>>
Windows also has the take ownership of folders that have a denied access.
But I dont know if this would work.

Right-click the folder that you want to take ownership of, and then click Properties.
2. Click the Security tab, and then click OK on the Security message (if one appears).
3. Click Advanced, and then click the Owner tab.
4. In the Name list, click your user name, or click Administrator if you are logged in as Administrator, or click the Administrators group. If you want to take ownership of the contents of that folder, select the Replace owner on subcontainers and objects check box.
5. Click OK, and then click Yes when you receive the following message:
You do not have permission to read the contents of directory folder name. Do you want to replace the directory permissions with permissions granting you Full Control?

All permissions will be replaced if you press Yes.
Note folder name is the name of the folder that you want to take ownership of.
6. Click OK, and then reapply the permissions and security settings that you want for the folder and its contents.

Good Luck

If you are used a strong encrypting software, without a lot of financial effort you can?t recover your data. Usually reinstall the encrypting software is not a solution. But how I say all this depends how strong is the used software.