"a single website of mine (affiliated) can NOT be accessed from my computer."
Not sure if i understand what you mean by the above quote which might help resolve your issue (ambiguity is never a helping factor). 1.What browser are you using? 2.Have you tried different browsers to access said website. 3. If it's a questionable website(like possibly blacklisted for malware) it could get blocked by anti-malware software on your computer(such as any hosts file modifications). 4. If using Internet Explorer make sure it did not get added to your "Restricted Sites"(start-control panel-internet options-security(tab)-Resticted Sites then "Sites" button then remove site if listed there). 5. If it's only been a few days since this has occurred you can try flushing your DNS Resolver Cache
Start-Run-then type "cmd" then in cmd prompt type "ipconfig /flushdns"
*do not type quotation marks*
Should then read:
Windows IP Configuration
Successfully flushed the DNS Resolver Cache.