<?xml version="1.0" encoding="us-ascii"?><InstanceReport xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><Version>2.4.0.8</Version><ReportLongName>001100 - Disclosure - Restricted Investment Balances</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column FlagID="0"><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

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</LabelSeparator><Level>2</Level><ElementName>us-gaap_RestrictedAssetsDisclosureTextBlock</ElementName><ElementPrefix>us-gaap_</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole>verboseLabel</PreferredLabelRole><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="FROM_Feb02_2013_TO_Aug02_2013" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;p style='margin-top:0pt; margin-bottom:0pt'&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;font-weight:bold;margin-left:0px;"&gt;Note &lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;font-weight:bold;"&gt;3&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;font-weight:bold;"&gt;: &lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;font-weight:bold;"&gt;Restricted &lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;font-weight:bold;"&gt;Investment Balances&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;font-weight:bold;"&gt; -&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;font-weight:bold;"&gt; &lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;Short-term and long-term investments&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt; include restricted balances pledged as collateral &lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;primarily &lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;for the Company's extended &lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;protection plan&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt; program&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;.  Restricted balances included in short-term investments we&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;re $&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;163&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt; &lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;million&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt; at&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt; &lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;August 2, 2013&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;, $&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;1&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;36&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt; million&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt; at &lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;August 3, 2012&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;, and $&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;12&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;3&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt; million at &lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;February 1, 2013&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;.  Restricted balances included in long-term investments were $&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;230&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt; &lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;million at &lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;August 2, 2013&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;, $&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;313&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt; million at &lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;August 3, 2012&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;, and $&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;263&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt; million at &lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;February 1, 2013&lt;/font&gt;&lt;font style="font-family:Times New Roman;font-size:11pt;"&gt;.&lt;/font&gt;&lt;/p&gt;&lt;p style='margin-top:0pt; margin-bottom:0pt'&gt;&amp;#160;&lt;/p&gt;</NonNumbericText><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>nonnum:textBlockItemType</ElementDataType><SimpleDataType>na</SimpleDataType><ElementDefenition>The entire disclosure for assets that are restricted in their use, generally by contractual agreements or regulatory requirements. 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