Friday

7:00 AM: Download Internet Explorer 8 to play with over the weekend.
6:30 PM: Get home from work and running, attempt to install IE8 while eating dinner.
6:45 PM: Installation fails with a permissions issue. Run SubInAcl's permissions reset command, since that solved a similar issue with Windows XP SP3.
7:00 PM: Notice massive slowdown after restart, and also that pretty much nothing works (RPC Service failing to start). System restore doesn't work either, since its service won't start.
7:15 PM: Go across the street to apartment complex's computer to look up which files to copy for a manual system restore.
7:30 PM: Boot with Windows CD that came with the computer (it came with XP Home, but afterward I got XP Pro for cheap from my school's MSDN academic alliance account), copy default system registry in order to access system restore files, boot with default registry to discover system restore files have been deleted. Flip.
8:00 PM: Drive to friend's house to borrow XP Pro install CD, since mine is backed up to a hard drive at my girlfriend's house 4 hours away. Call girlfriend, have her read my product key to me over the phone. Realize all backups of files are at her house, and that I don't have enough hard drive space to make other backups. Will have to try repair installs instead of clean installs.
8:30 PM: Repair install Windows XP Pro, find out my XP Pro product key doesn't work on this install CD. Flip. Will take the 5th on what happened after this.
9:00 PM: Horrible realization that the reason the XP Pro product key didn't work was because friend's install CD is SP1. Attempt to install SP3, which I had on the drive.
9:20 PM: SP3 installation fails with permissions issue. Cruelty. Run SubInAcl again. Attempt SP3 again.
10:00 PM: SP3 installation finishes, but has pretty much the same issue as it did at 7:00 PM. Discover that a terrible hybrid of Internet Explorer 6 and 7 are installed, due to mixing my previous IE7 install, my attempted IE8 installation, and XP SP1's IE6 installation. Attempts to install IE7 or IE8 or to reinstall SP3 fail because Cryptographic Services can't start up to verify the integrity of the files.
12:00 AM: Give up, go to bed.

Saturday

7:00 AM: Car alarm outside wakes me up. Make coffee, go to work, which is deserted, and get my work laptop. Buy groceries to make breakfast.
8:00 AM: Search in vain for install media for XP Pro with SP2, hoping to do a repair install.
11:00 AM: Find a backup XP Pro with SP2 install CD, which I thought I didn't have. Initiate repair install.
12:30 PM: Product key doesn't work. Call girlfriend, who e-mails key to me. Realize I'd misheard a letter earlier.
12:40 AM: Product key still doesn't work. Symptom of events at 8:00 PM last night?
1:00 PM: Make a slipstreamed CD with SP3 and IE7 out of the disc found at 11:00 AM. Also make a BartPE disc for kicks.
2:00 PM: Product key doesn't work on slipstreamed CD, no surprise. Come up with new plan. 1) Download GParted LiveCD to shrink main partition. 2) Clean install slipstreamed Windows onto new partition. 3) Copy over files from main partition. 4) Nuke old partition and resize new partition. Girlfriend agrees to make heroic drive to my house.
2:30 PM: GParted can't resize because NTFS journal is dirty. Boot back to Windows CD, run chkdsk, which takes flipping forever. Go for a run.
3:30 PM: Boot into GParted again, resize old partition and create new one. Success.
3:40 PM: Attempt clean install of slipstreamed Windows onto new partition.
4:15 PM: Product key doesn't work. WTF?!
4:20 PM: Realize the XP Pro CD I found at 11:00 AM was not mine, but a backup a friend had made for when I'd fixed his computer 1.5 years ago. Explains why product key doesn't work. Wait for girlfriend to arrive with my XP Pro CD.
6:00 PM: Girlfriend arrives. Copy actual XP Pro CD to work laptop, slipstream in SP3 and IE7. Go to get Chinese takeout.
6:40 PM: Start installing Windows. Eat Chinese food.
6:50 PM: Product key accepted! Watch Hulu on work laptop with girlfriend.
8:00 PM: Reinstalling all programs and copying over settings... the end is in sight.

Thanks to David (friend) and Kristen (girlfriend) for assistance in this matter.

Lessons learned:

1) Don't install Microsoft software the week it comes out.
2) Remember that there was a time before XP SP2, and that time is not compatible with you if you have Internet Explorer 7 installed...
3) Only having an off-site backup is not sufficient - have an on-site backup too.