What is the most secure encryption algorithm to encrypt my password database? The password manager I use lets me choose an algorithm from the list below in order to encrypt my password database:

Microsoft Base Cryptographic Provider v1.0:


RC2-128
RC4-128
DES-56
3DES TWO KEY-112
3DES-168


Microsoft Enhanced Cryptographic Provider v1.0:


RC2-128
RC4-128
DES-56
3DES TWO KEY-112
3DES-168


Microsoft Enhanced RSA And AES Cryptographic Provider:


RC2-128
RC4-128
DES-56
3DES TWO KEY-112
3DES-168
AES-128
AES-192
AES-256


Microsoft RSA SChannel Cryptographic Provider:


AES-128
AES-256
RC2-128
RC4-128
DES-56
3DES TWO KEY-112
3DES-168


Microsoft Strong Cryptographic Provider:


RC2-128
RC4-128
DES-56
3DES TWO KEY-112
3DES-168


The default value is RC4 with the key length of 128 bits from Microsoft Strong Cryptographic Provider.

Now I have two questions: 


Which algorithm is the most secure? 
Does the algorithm provider matter?


Edit:

@mikeazo♦: I use Kaspersky Password Manager v5.(Unluckily, I don't have enough reputation to leave a comment!)
The number denotes the size of the key used - for a given algorithm, the larger the key, the more secure it is - hence AES-256 is better than AES-192 is better than AES-128.

The key size is measured in bits - so in terms of its protection against a brute force attack (attacker tries all possible keys) a 256 bit password is not twice as hard to break as a 128 bit password, it is 34000000000000000000000000000000000000 times as hard.

But there are other ways to attack encryption - exploiting mathemetical flaws/coincidences in the algorithm. Although 3DES uses 3 56 bit keys, the effective key size is only around 120 bits. But it is still considered better than RC2-128.


  Which algorithm is the most secure?


Of those you have listed, AES-256


  Does the algorithm provider matter?


No. In effect, it is just a list of available algorithms. But you do need to ensure the algorithm is available anywhere you want to decode the data.