Symantec Corp. (Nasdaq: SYMC), the largest provider of security software, is likely to confirm prior guidance for lower-than-expected fourth-quarter results on Wednesday.

The developer of popular products including Norton Anti-Virus software preannounced that lower revenue had trimmed per-share earnings to only 38 cents from the previous estimates of 42 cents, on revenue around $1.69 billion.

A year ago, the Sunnyvale, Calif., software company reported fourth-quarter earnings of 38 cents per share on revenue of $1.67 billion.

CEO Enrique Salem blamed slower shipments of PCs that require the products, perhaps because consumers are awaiting the shipment of the new Windows 8 from Microsoft Corp. (Nasdaq: MSFT), the world's biggest software company, later this year.

As well, Symantec's storage business was weaker than expected, lowering both quarterly sales and profit.

Shares of the security software giant dipped 10 percent last week on the preannouncement news. They closed Tuesday at $16.45, down 8cents, giving the company a market capitalization of $12 billion, well below their 52-week high of $20.50.

Analysts raised questions whether the company might need to restructure, possibly changing it product mix, much of which came through the acquisition of companies like Veritas Software and Verisign. Others wondered if it was just having problems changing from traditional ways of selling software built into systems to contemporary software-as-a-service models.

At Jefferies, analyst Aaron Schwartz kept Symantec a buy with a target of $20 but said it experienced a purchasing pause ahead of refreshment of its BackupExec and NetBackup products scheduled later this year.

At FBR Capital, analyst Daniel Ives maintained an outperform rating on the company because it should benefit from new product releases in the new fiscal year that began last month.

So far in 2012, Symantec shares are up 5.6 percent, compared with rivals including Check Point Software Technologies Ltd. (Nasdaq: CHKP), up 10.6 percent and Imperva Inc. (Nasdaq: IMPV), flat for the year but up 45 percent from its November initial public offering. Other enterprise software companies including Microsoft (Nasdaq: MSFT) and CA Technologies (NYSE: CA) sell security software as part of their overall offerings.