Need advice

Using Tor browser, which uses Firefox v17.0.9, I have encountered a problem where "System Restore" fails.

Upon opening Tor, wherein the zoom must be manipulated using ctrl + mouse wheel. In zooming to make text readable it also zoomed the icons on the Desktop. (though not all. Only those linked to executables.) Screen resolution is not affected. Usually I could adjust this sizing with the mouse wheel but that failed this time. (this happened once before)The scrolling apparently linked to Control Panel|Display as I found that my setting of 125% was changed to 150%. Resetting to 125 reduced the size accordingly.

I decided to restore the system to an earlier date but the restore failed to initialize. As ("please wait...........system restore is initializing") and sits there for hours. Ended with "System Restore Failed, Windows can't start". Useing restore to undo latest restore fails as well as trying earlier restore points.You must shut down manually as you can't exit windows. I attempted to restore in 'SAFE MODE' with similar result. This resulted in a "System Start Repair" dialog. I followed the prompts but to no avail. After this attempt, the machine booted and worked normally with the exception of system restore.

I created back up disks when I set the machine up in 2010, but I'm wondering if it is safe to use these in view of system restore failure to perform. After the afore mentioned attempts to repair, the system works. Boots and performs as normal though the icons are still screwed up. Much smaller, but not normal. However, restore still won't go past the "...........initializing.........." screen. I do not have the OS on disk, so if the back up disks fail as well, I will be had. I can live with the icons, but I do want to regain use of "System Restore" as I use it often.

10/31 --------- 9:15 AM
Ran restore again in windows--------same result-----------won't go past the "...........initializing.........." screen
9:45AM Turned computer off w/o exiting windows-------
Ran restore again in Safe Mode--------same result-----------won't go past the "...........initializing.........." screen
11:AM Turned computer off w/o exiting windows

11:05AM Turned computer on----------Computer displays prompt to auto run "CHKDSK" 3 stage File verification-----------Allowed auto run w/follwing results------------.

stage 1="deleted a number of "corrupted file attributes--------file#----------"
stage 2="Verifying indexes" =307 indexes scanned=212 Unindexed files recovered"
Stage 3="Verifying security indexes"

Upon completion of CHKDSK= normal windows boot with notification of failed restore op dialog. Opted not to run restore----------Exited windows------------shut down computer.
Turned computer on--------Normal boot and functions normaly.

Any help will be appreciated.

System Info as follows.
Firefox 17.0.9
Win 7 Home Premium (x64) SP 1 (build 7601)
Install Language: English (United States)
ATI Radeon HD 5700 Series [Display adapter]
DELL ST2210 [Monitor] (21.7"vis, s/n NPMG805V2U9U, June 2010)
Dell Inc. Studio XPS 8100
2.93 gigahertz Intel Core i7 870
32 kilobyte primary memory cache
1024 kilobyte secondary memory cache
8192 kilobyte tertiary memory cache
64-bit ready
Multi-core (2 total)
Hyper-threaded (4 total) Board: Dell Inc. 0G3HR7 A00
Serial Number: ..CN7360407J00JO.
Bus Clock: 133 megahertz
BIOS: Dell Inc. A05 07/08/2010

AVG Internet Security Version 14.0.0.4158
Norman Malware Cleaner Version 2,07,06