How to change address bar search provider in firefox?

In order to change the search provider of address bar in firefox, perform following steps:

1. In address bar type about:config and press enter.

2. Then you will receive following warning message. Accept it to see the configuration option.

3. Enter keyword.url in the filter and locate the parameter keyword.url.(Here default search provider is yahoo)

Effective Google searching

Google serves some 80 percent of all search queries on the Internet, making it by far the most popular search engine. Its popularity is due not only to excellent search effectiveness, but also extensive querying capabilities. However, we should also remember that the Internet is a highly dynamic medium, so the results presented by  Google are not always up-to-date – some search results might be stale, while other relevant resources might not yet have been visited by Googlebot (the automatic script that browses and indexes Web resources for Google).
Table 1 presents a summary of the most important and most useful query operators along with their descriptions, while Figure 1 shows document locations referred to by the operators when applied to Web searches. Of course, this is just a handful of examples – skilful Google querying can lead to much more interesting results. Hunting for Prey Google makes it possible to reach not just publicly available Internet resources, but also some that should never have been revealed.

Table 1

Operator	Description	Sample query
site	restricts results to sites within the specified domain	site:google.com fox will find all sites containing the word fox, located within the *.google.com domain
link	restricts results to sites containing links to the specified location	link:www.google.com will return documents containing one or more links to www.google.com
intitle	restricts results to documents whose title contains the specified phrase	restricts results to documents whose title contains the specified phrase
allintitle	restricts results to documents whose title contains all the specified phrases	allintitle:fox fire will find all sites with the words fox and fire in the title, so it's equivalent to intitle:fox intitle:fire
inurl	restricts results to sites whose URL contains the specified phrase	inurl:fox fire will find all sites containing the word fire in the text and fox in the URL
allinurl	restricts results to sites whose URL contains all the specified phrases	allinurl:fox fire will find all sites with the words fox and fire in the URL, so it's equivalent to inurl:fox inurl:fire
filetype, ext	restricts results to documents of the specified type	filetype:pdf fire will return PDFs containing the word fire, while filetype:xls fox will return Excel spreadsheets with the word fox
numrange	restricts results to documents containing a number from the specified range	numrange:1-100 fire will return sites containing a number from 1 to 100 and the word fire. The same result can be achieved with 1..100 fire
inanchor	restricts results to sites containing links with the specified phrase in their descriptions	inanchor:fire will return documents with links whose description contains the word fire (that's the actual link text, not the URL indicated by the link)
allintext	restricts results to documents containing the specified phrase in the text, but not in the title, link descriptions or URLs	allintext:"fire fox" will return documents which contain the phrase fire fox in their text only
+	specifies that a phrase should occur frequently in results	+fire will order results by the number of occurrences of the word fire
-	specifies that a phrase must not occur in results	-fire will return documents that don't contain the word fire
""	delimiters for entire search phrases (not single words)	"fire fox" will return documents containing the phrase fire fox
.	wildcard for a single character	fire.fox will return documents containing the phrases fire fox, fireAfox, fire1fox, fire-fox etc.
*	wildcard for a single word	fire * fox will return documents containing the phrases fire the fox, fire in fox, fire or fox etc.
|	logical OR	"fire fox" | firefox will return documents containing the phrase fire fox or the word firefox