vista explorer.exe application error when using start menu search

this just started happening: whenever i type anything into the search box in the start menu, i get an error that says "the instruction at 0xXXXXXXXX referenced memory at 0xXXXXXXXX. the memory could not be read. click on ok to terminate the program"

clicking ok restarts explorer.exe, and this happens in safe mode, as well as regular boot.

here is what event viewer says:

Log Name: Application
Source: Microsoft-Windows-EventSystem
Date: 12/27/2011 8:32:21 PM
Event ID: 4609
Task Category: Event System
Level: Error
Keywords: Classic
User: N/A
Computer: Prescott
Description:
The COM+ Event System detected a bad return code during its internal processing. HRESULT was 8007043c from line 45 of d:\vistartm\com\complus\src\events\tier1\eventsystemobj.cpp. Please contact Microsoft Product Support Services to report this error.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="Microsoft-Windows-EventSystem" Guid="{899daace-4868-4295-afcd-9eb8fb497561}" EventSourceName="EventSystem" />
<EventID Qualifiers="49152">4609</EventID>
<Version>0</Version>
<Level>2</Level>
<Task>16</Task>
<Opcode>0</Opcode>
<Keywords>0x80000000000000</Keywords>
<TimeCreated SystemTime="2011-12-28T02:32:21.000Z" />
<EventRecordID>1623</EventRecordID>
<Correlation />
<Execution ProcessID="0" ThreadID="0" />
<Channel>Application</Channel>
<Computer>Prescott</Computer>
<Security />
</System>
<EventData>
<Data Name="param1">d:\vistartm\com\complus\src\events\tier1\eventsystemobj.cpp</Data>
<Data Name="param2">45</Data>
<Data Name="param3">8007043c</Data>
</EventData>
</Event>

what could cause this?

system restore does not fix this problem, fyi

the problem has gotten worse. explorer.exe now won't load the desktop fully without the same error popping up. clicking ok just restarts the process. like an endless loop. i managed to get into the start menu and load firefox so i can type this, but as for saving my files via windows explorer, i'm afraid that option has gone out the window. i'm calling it quits with vista, this error has won. i'll put the drive in another computer and pull the files off, and then install xp. it's a pentium 4, so i think xp will be a better fit anyway.

so long vista; you were loved, but then you pissed me off.