When your hard disk runs out of free space windows Vista will start to give you a warning about low disk space. In the beginning its useful to know that you have run out of space. But Windows continues to give warning until you free up some space. This gets irritating and you don't have any setting to stop this.
Vista constantly checks the drives for the low disk space which uses resources and slows down the system.
Follow these easy steps to disable this annoying warning message
--- Go to registry by typing regedit in run box. OR Type regedit in start menu search box and hit Enter.
---Then locate this key in the left pane
--- Under policies look for the sub key named Explorer if its not present you have to create the key. To create the key right click on Policies and select New Key. A new key named New Key #1 will be created below Policies. Name that key as Explorer.
--- Now select the Explorer key and in the right pane right click and select New --> DWORD(32-bit) Value and name it NoLowDiskSpaceChecks--- Now to edit its value double click on it and enter value '1' instead of '0' in the value data field. Click OK.--- This is how it should look
--- Close the registry.
No more annoying warning messages for Low disk Space.
To Re-enable the warning messages replace '1' with '0' or delete the DWORD value created.
Note: In XP these entries might be present already you just need to edit the value to from '0' to '1'