what's wrong with my computer?

I was wondering if anyone could help me please!
Every time I open Internet Explorer I get an error message saying:
"Internet Explorer has encountered a problem and needs to close. We are sorry for the inconvenience." etc.
It asks if i want to send an error report or not, and it says:
"To see what data this error report contains, click here"
So if I click here it says:
"AppName: iexplore.exe AppVer: 6.0.2900.2180 ModName: wininet.dll
ModVer: 6.0.2900.2781 Offset: 0001b810"

If I click on either "send" or "don't send", Internet Explorer closes, but if I just ignore it it seems to be ok, and I can browse as usual.

The same thing happens when I try to use msn messenger
It says:
"Messenger has encountered a problem and needs to close. We are sorry for the inconvenience." etc.

And when I click here it says:
"AppName: msnmsgr.exe AppVer: 7.5.311.0 ModName: wininet.dll
ModVer: 6.0.2900.2781 Offset: 0001b810"

Same thing though, if I ignore it, then msn works ok.

I looked up that wininet.dll and it says:
"DLL File: wininet or wininet.dll
DLL Name: Internet Extensions for Win32

Description:
wininet.dll is a module that contains Internet-related functions used by Windows applications.

Note: wininet.dll is a process which the Troj/Zlob-AO trojan tries to disguise itself as under the true process name of %systemroot%\mscornet.exe. This program is a registered security risk and should be removed immediately."

So I searched on my computer and the only wininet.dll file seems to be the normal windows one.

I hope someone can help me figure out what's going on. Do I have a virus? Or is something wrong with windows or anything else?

Any help would be greatly appreciated!!