Toshiba Laptop Freezes

I installed IE v7 beta (please don't tell me how foolish that was!!) on this computer and then couldn't get online. I was able to uninstall it but now I have problems that seem related to that. One, some of the basic things from Win XP are missing such as ability to change pointers, no games available, etc. Any suggestions on how to get those back would be greatly appreciated. I'm really trying to avoid doing recovery because I have never backed up my computer and basically don't know how, yet. Two, I have lost the ability to use Firefox; I have uninstalled, downloaded and reinstalled it and it still won't connect to the internet. Three, it seems I'm unable to change my homepage from MSN to anything else I'd like even though I've tried Tools, Interned Options and Homepage numerous times; is there any other way to unlock that? Four and most annoying of all is that my computer freezes up sporatically, but too often. It seems to occur when I leave it idle for a short period of time, like 5 minutes or so.

Based on the suggestion that "there's never too much information", the following is info on my computer from Belarc.
TOSHIBA Satellite A75 PSA70U-004004.
Windows XP Home Edition Service Pack 2 (build 2600).
448 Megabytes Installed Memory.
Drives - 60.01 Gigabytes Usable Hard Drive Capacity - 19.02 Gigabytes Hard Drive Free Space - MATSHITA DVD-RAM UJ-820S [CD-ROM drive] - IC25N060ATMR04-0 [Hard drive] (60.01 GB) -- drive 0, s/n MRG30HK3KGE4NH, rev MO3OAD4A, SMART Status: Healthy. Communications - TOSHIBA Software Modem - 1394 Net Adapter - Atheros AR5004G Wireless Network Adapter
Physical Address: 00:90:96:C5:4F:33 - Realtek RTL8139/810x Family Fast Ethernet NIC - Wireless-G Notebook Adapter v.2.0 - primary Auto IP Address: 192.168.1.109 / 24
Gateway: 192.168.1.1
Dhcp Server: 192.168.1.1
Physical Address: 00:0F:66:BE:948
Networking Dns Servers: 68.87.71.226
68.87.73.242

Other Devices - Texas Instruments OHCI Compliant IEEE - 1394 Host Controller - Microsoft AC Adapter - Microsoft ACPI-Compliant Control - Method Battery - SMC IrCC - Fast Infrared Port, SP1 - Standard 101/102-Key or Microsoft Natural PS/2 Keyboard - Alps Pointing-device [Mouse] -
USB Root Hub (3x) - Virtual Bus

Virus Protection - Norton AntiVirus Version 12.20 - Virus Definitions Version 3/5/2006 Rev 6 - Last Disk Scan on Monday, February 27, 2006 2:48:08 PM -
Realtime File Scanning On

Missing Microsoft Security Hotfixes - All required security hotfixes (using the 02/14/2006 Microsoft Security Bulletin Summary) have been installed.
Installed Microsoft Hotfixes [Back to Top]
.NETFramework
1.1
S867460 on 9/19/2004 (details...)
M886903 on 2/11/2005 (details...)
DataAccess
Q832483 on 12/2/2003 (details...)
Internet Explorer
SP2 (SP2)
Step By Step Interactive Training
SP2
KB898458 on 6/15/2005 (details...)
Windows Media Player 10
SP0
KB911565 on 2/17/2006 (details...)
Windows Media Player
WM819639 (details...)
SP0
KB911564 on 2/17/2006 (details...)
Windows XP
SP2
KB811113[SP] on 9/20/2004 (details...)
SP3
KB834707 on 10/16/2004 (details...)
KB867282 on 2/11/2005 (details...)
KB873333 on 2/11/2005 (details...)
KB873339 on 12/15/2004 (details...)
KB883939 on 6/15/2005 (details...)
KB884020 on 3/2/2005 (details...)
KB885250 on 2/11/2005 (details...)
KB885835 on 12/15/2004 (details...)
KB885836 on 12/15/2004 (details...)
KB885884 on 10/16/2004 (details...)
KB886185 on 12/15/2004 (details...)
KB887472 on 2/11/2005 (details...)
KB887742 on 2/24/2005 (details...)
KB888113 on 2/11/2005 (details...)
KB888302 on 2/11/2005 (details...)
KB890046 on 6/15/2005 (details...)
KB890047 on 2/11/2005 (details...)
KB890175 on 1/12/2005 (details...)
KB890859 on 4/15/2005 (details...)
KB890923 on 4/15/2005 (details...)
KB891781 on 2/11/2005 (details...)
KB893066 on 4/15/2005 (details...)
KB893086 on 4/15/2005 (details...)
KB893756 on 8/13/2005 (details...)
KB893803 on 4/15/2005 (details...)
KB893803V2 on 5/19/2005 (details...)
KB894391 on 8/13/2005 (details...)
KB896358 on 6/15/2005 (details...)
KB896422 on 6/15/2005 (details...)
KB896423 on 8/13/2005 (details...)
KB896424 on 11/9/2005 (details...)
KB896428 on 6/15/2005 (details...)
KB896688 on 10/14/2005 (details...)
KB896727 on 8/13/2005 (details...)
KB898461 on 6/30/2005 (details...)
KB899587 on 8/13/2005 (details...)
KB899588 on 8/13/2005 (details...)
KB899591 on 8/13/2005 (details...)
KB900725 on 10/14/2005 (details...)
KB901017 on 10/14/2005 (details...)
KB901214 on 7/15/2005 (details...)
KB902400 on 10/14/2005 (details...)
KB903235 on 7/15/2005 (details...)
KB904706 on 10/14/2005 (details...)
KB905414 on 10/14/2005 (details...)
KB905749 on 10/14/2005 (details...)
KB905915 on 12/15/2005 (details...)
KB908519 on 1/11/2006 (details...)
KB910437 on 12/15/2005 (details...)
KB911927 on 2/17/2006 (details...)
KB912919 on 1/6/2006 (details...)
KB913446 on 2/17/2006 (details...)
Click here to see all available Microsoft security hotfixes for this computer.
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