This series, brought to you by Yahoo! Finance, looks at which upgrades and downgrades make sense, and which ones investors should act on. Today, our headlines feature a mild improvement in sentiment on Hewlett-Packard (HPQ -0.36%), balanced by cloudier outlooks for Google (GOOGL 0.69%) and Ruby Tuesday (RT). Let's dive right in.

A happy day for Hewlett
Leading off with the day's happiest news, shareholders of PC manufacturer Hewlett-Packard can breathe a sigh of relief: Their stock is no longer a sell -- at least, according to Mizuho Securities.

This morning, Mizuho announced it is removing its underperform rating from HP shares, and upgrading to neutral in response to the company progress update that was issued yesterday. According to HP, generally accepted accounting principles earnings in fiscal 2014 should amount to between $2.85 and $3.05 per share -- quite an improvement over last year's $6.41-per-share net loss.

But the news isn't all good. HP said it only expects to generate about $9 billion to $9.5 billion in cash from operations this year; after deducting capital spending, it will be left with free cash flow of only $6 billion to $6.5 billion. That's actually less than the $6.9 billion in cash profits HP generated last year -- so there's at least an argument to be made that the company is getting sicker, even if it does succeed in reporting a GAAP profit.

Meanwhile, the simple fact that HP shares cost $22 and change means that Mizuho's projection of a $22 target price suggests investors can expect to see no growth at all in the shares over the next 12 months. That may mean the shares are now fairly enough valued that you need not sell them -- but it's hardly a compelling argument to buy.

Google going lower?
Continuing the tech theme, we turn now to Google, which got hit with bad news this morning. After crunching some numbers on the search giant, analysts at Telsey Advisory Group concluded that Google is unlikely to gain the 100 points it would need to hit Telsey's old price target of $966. The research firm is therefore backing off that target and reducing its price target to $900.

Granted, this is not horrible news. With Google shares changing hands for $866 and change today, it suggests the stock is still about 4% undervalued. Investors who look at the stock and see a 25 P/E ratio supported by only 15% projected earnings growth rates -- and think Google looks overvalued -- may be encouraged to hear that Telsey still sees the potential for some upside profits.

Personally, though, I do not see the upside in this one. Free cash flow at Google, while strong at about $12.3 billion in cash profits generated over the past year, is still not strong enough to justify the stock price. Even crediting Google for its enormous cash hoard, and valuing it on superior cash flows (about 6% ahead of reported net income), I still get an enterprise value-to-free cash flow ratio of nearly 20 on Google. That seems high relative to the 15% growth rate.

Meanwhile, in apparent contradiction of analysts' expectations for earnings growth, free cash flow at Google so far this year is actually trending downward from 2012 (when the company threw off $13.3 billion in cash profits). Long story short, while I still like Google a lot as a business, the stock looks unattractive at today's prices. I wouldn't buy it at $866, and I certainly wouldn't pay the $900 a share that Telsey is promising.

Goodbye, Ruby Tuesday!
Finally, an easy come, easy go story for Ruby Tuesday investors. Yesterday, as you may recall, analysts at B. Riley clambered way out on a limb to initiate coverage of the struggling restaurateur with a buy rating and a $10 price target. Given that Riley chose to make this bold call just hours before Ruby Tuesday reported its fiscal first-quarter earnings results, you have to figure the analysts were confident in their prediction.

Confident, but wrong. 

Last night, Ruby Tuesday reported a $0.37-per-share loss on an 11% decline in revenue for its fiscal first quarter -- even worse than the $0.05-per-share loss Wall Street had been expecting, and much worse than the $0.04 profit that Ruby Tuesday earned a year ago.

Today, two analysts threw in the towel on Ruby Tuesday in quick succession, with Telsey (yes, them again) cutting its price target 25% to $6 and Raymond James reducing its rating from market perform to underperform. You can hardly blame them. At last report, Ruby Tuesday was doing less business annually than it did as far back as 2010, and losing money at its fastest pace... well, ever. The chain racked up $64 million in losses over the past 12 months.

If this is what Ruby Tuesday's turnaround is going to look like, it's easy to see why the analysts aren't impressed. To be honest, neither am I.

Fool contributor Rich Smith has no position in any stocks mentioned. The Motley Fool recommends Google. The Motley Fool owns shares of Google.