user1580: Considering the Bitcoin client for Windows 0.8.1:
So the best way (if I have already used up 100 keys) is to send bitcoins to different wallet and then to newly generated one?
When I want new keys, can I just delete old wallet from default location and WILL BE THE NEW ONE GENERATED AUTOMATICALY when turning on the client? 

user208: A wallet (by default) always contains 100 unused keys. Every time the client needs a new key (for a new address, for sending change to, or - in theory - for solo mining payouts), it takes the oldest address from the pool, and creates a fresh one to add.
This just means you need to backup every 100 transactions. No need to switch to a new wallet.

user2785: Run the client with the parameter -keypool=10000 to generate 10000 keys in your keypool.
Pros: Less backing up
Cons: Your wallet will be bigger (file size) and take maybe a few seconds extra to load

1580: <p><em>Considering the Bitcoin client for Windows 0.8.1:</em></p>

<p>So the best way (if I have already used up 100 keys) is to send bitcoins to different wallet and then to newly generated one?</p>

<p>When I want new keys, can I just delete old wallet from default location and WILL BE THE NEW ONE GENERATED AUTOMATICALY when turning on the client? </p>
 208: <p>A wallet (by default) always contains 100 <strong>unused</strong> keys. Every time the client needs a new key (for a new address, for sending change to, or - in theory - for solo mining payouts), it takes the oldest address from the pool, and creates a fresh one to add.</p>

<p>This just means you need to backup every 100 transactions. No need to switch to a new wallet.</p>
 2785: <p>Run the client with the parameter <code>-keypool=10000</code> to generate 10000 keys in your keypool.</p>

<p>Pros: Less backing up</p>

<p>Cons: Your wallet will be bigger (file size) and take maybe a few seconds extra to load</p>
