Windows Vista Vista multiple problems

Hi, I am new to this site and I am hoping to find some answers to my problems. I am not new at fixing computers but I am currently stuck from where I am now. Please Help! ><

1. I am using Internet Explorer 8 and having some "hanging" tabs. Where when I open a tab in the explorer it hangs there and says its "connecting..." and the only way to cancel the tab is to end program internet explorer via task manager, and sometimes I have to restart my computer because it frezes. I have tried the open internet explorer with no add ons>internet options>Manage add ons>disabled all non verified addons as well as addons that I didn't want. The problem still persists.
For more details here is a forum of the problem that I have that I found:
http://social.answers.microsoft.com...r/thread/9121047e-48ba-40fc-8396-829bdea39b32

2. I am getting desktop skin changes without my permission and I have run Malwarebytes 3 times quarentined all that showed up as a problem and still nothing changed. I have no more system restore points for my computer to restore to.

3. I have had a recent virus attack on my computer and have lost 50GB worth of memory. Its probably a no brainer but what ocourse of action should I take?? As i have said before I have no more system restore points for my computer to restore to as well.

4. Also I don't remember if Windows Defender is obsolete anymore but I can't update windows defender to a Code:0x80072efe. I am not sure if Windows defender is obsolete anymore I just remember vaguely that it has been ceased, but I am not sure. I have tried the solution on this forum:
http://social.answers.microsoft.com...l/thread/21938e1d-bdf6-47ae-846b-dca7315f6c2f
(command prompt>sfc /scannow) but the scan showed that there is an error but I cannot fix it at that point.

I have run TFC and nothing has changed, I also ran MBRCheck but it showed Found non-standard or infected MBR but it won't save a log. Also ran DDS the result was a bunch of gibberish and with "This program cannot be run in DOS mode" in the midst. I also Ran GMER can saved a log on my desktop and can't seem to see or find it at all.

So the only log that I have been able to save is the Malwarebytes:
Malwarebytes' Anti-Malware 1.50.1.1100
www.malwarebytes.org

Database version: 5586

Windows 6.0.6002 Service Pack 2
Internet Explorer 8.0.6001.18999

1/23/2011 10:57:21 PM
mbam-log-2011-01-23 (22-57-21).txt

Scan type: Full scan (C:\|D:\|)
Objects scanned: 254546
Time elapsed: 56 minute(s), 38 second(s)

Memory Processes Infected: 0
Memory Modules Infected: 0
Registry Keys Infected: 0
Registry Values Infected: 0
Registry Data Items Infected: 0
Folders Infected: 0
Files Infected: 0

Memory Processes Infected:
(No malicious items detected)

Memory Modules Infected:
(No malicious items detected)

Registry Keys Infected:
(No malicious items detected)

Registry Values Infected:
(No malicious items detected)

Registry Data Items Infected:
(No malicious items detected)

Folders Infected:
(No malicious items detected)

Files Infected:
(No malicious items detected)

 

First of all: what version of windows are you running?

Second of all: do the skin changes occur with the taskbar (eg. change colours, styles) or just background wallpaper changes?

As for windows defender, your better off buying an antivirus program like Trend Micro or Norton etc. than relying on that